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ICHEP 2020
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virtual conference
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Rupert Leitner
(Charles University (CZ)),
Zdenek Dolezal
(Charles University (CZ))
Description
40th International Conference on High Energy Physics
ICHEP is a series of international conferences organized by the C11 commission of the International Union of Pure and Applied Physics (IUPAP). It has been held every two years since more than 50 years, and is the reference conference of particle physics where most relevant results are presented.
At ICHEP, physicists from around the world gather to share the latest advancements in particle physics, astrophysics/cosmology, and accelerator science and discuss plans for major future facilities.
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Neutrino Physics: Session I - PremiereConveners: Thomas Schwetz, Ryan Patterson (California Institute of Technology)
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1
Global fits to neutrino masses and mixings
In this talk, I will describe the updated status of global analyses to neutrino oscillation data in the three-flavor framework, with an emphasis on the recent hints in favor of normal mass ordering and maximal CP violation. I will focus on the current knowledge of the oscillation parameters as well as on the improvements that can be expected in the near future.
Speaker: Dr Mariam Tórtola (IFIC (CSIC/Universitat de València)) -
2
Direct comparison of sterile neutrino constraints from cosmological data, electron neutrino disappearance data and muon neutrino to electron neutrino appearance data in a 3+1 model
We present a quantitative, direct comparison of constraints on sterile neutrinos derived from neutrino oscillation experiments and from Planck data, interpreted assuming standard cosmological evolution. We extend a $1+1$ model, which is used to compare exclusions contours at the 95% CL derived from Planck data to those from $\nu_{e}$-disappearance measurements, to a $3+1$ model. This allows us to compare the Planck constraints with those obtained through $\nu_{\mu}\rightarrow\nu_{e}$ appearance searches, which are sensitive to more than one active-sterile mixing angle. We find that the cosmological data fully exclude the allowed regions published by the LSND, MiniBooNE and Neutrino-4 collaborations, and those from the gallium and rector anomalies, at the 95% CL. Compared to the exclusion regions from the Daya Bay $\nu_{e}$-disappearance search, the Planck data are more strongly excluding above $|\Delta m^{2}_{41}|\approx 0.1\,\mathrm{eV}^{2}$ and $m_\mathrm{eff}^\mathrm{sterile}\approx 0.2\,\mathrm{eV}$, with the Daya Bay exclusion being stronger below these values. Compared to the combined Daya Bay/Bugey/MINOS exclusion region on $\nu_{\mu}\rightarrow\nu_{e}$ appearance, the Planck data is more strongly excluding above $\Delta m^{2}_{41}\approx 5\times 10^{-2}\,\mathrm{eV}^{2}$, with the exclusion strengths of the Planck data and the Daya Bay/Bugey/MINOS combination becoming comparable below this value.
Speaker: Justin Evans (University of Manchester (UK)) -
3
Neutrino oscillations, flavor theories and dark matter
After a brief review of the status of neutrino oscillation
experiments I discuss some recent results on flavor extensions of the
standard model and their possible implications for dark matter.Speaker: Jose Valle -
4
Extraction of the optical potential for final state nucleons and $\Delta$ resonances for electron and neutrino scattering on nuclear targets
Precise modeling of neutrino (and electron) interactions on nuclear targets is essential for neutrino oscillations experiments. The modeling the energy of final state leptons and nucleons in quasielastic scattering on bound nucleons requires knowledge of both the removal energy of the bound nucleon as well as the Coulomb and nuclear optical potentials for the final state nucleon in the field of the spectator (A-1) nucleus. We compare the values of the optical potential for final state protons extracted from electron scattering data on nuclear targets in the quasielastic region to the extracted values of the optical potential for $\Delta$ resonances in the final state. This is the first measurement of the optical potential for the $\Delta$ resonance. We find that the optical potential for a $\Delta$ resonance in the final state is larger than the optical potential for a final state proton.
Speaker: Arie Bodek (University of Rochester (US)) -
5
Constraints on nonstandard interactions and the neutron radius from coherent elastic neutrino-nucleus scattering experiments
There are expectations for achieving new measurements of the coherent elastic neutrino-nucleus scattering (CENNS) by
using electron antineutrinos from reactor experiments and through muon (electron) neutrinos from spallation neutrino
sources (SNS). The first scenario takes into account very low energy neutrinos while the second one includes
relatively higher energy neutrinos. These measurements would allow improve our knowledge about standard and beyond
Standard Model physics, for instance as regards the nuclear radius and nonstandard interactions, respectively. In
this talk we will show constraints on the neutron radius and nonstandard parameters obtained from CENNS processes in
experiments of both reactor neutrinos and SNS. We will also display that a combination of several experiments could
give rise to more robust constraints on the parameters mentioned above.Speaker: Alexander Parada Valencia (Universidad Santiago de Cali) -
6
Neutrino Portals to Dark Matter
We explore the possibility that dark matter interactions with Standard Model particles are dominated by interactions with neutrinos. We examine whether it is possible to construct such a scenario in a gauge invariant manner. We first study the coupling of dark matter to the full lepton doublet and confirm that this generally leads to the dark matter phenomenology being dominated by interactions with charged leptons. We then explore two different implementations of the neutrino portal in which neutrinos mix with a Standard Model singlet fermion that interacts directly with dark matter through either a scalar or vector mediator. In the latter cases we find that the neutrino interactions can dominate the dark matter phenomenology. Present neutrino detectors can probe dark matter annihilations into neutrinos and already set the strongest constraints on these realisations. Future experiments such as Hyper-Kamiokande, MEMPHYS, DUNE, or DARWIN could allow to probe dark matter-neutrino cross sections down to the value required to obtain the correct thermal relic abundance.
Speaker: Salvador Rosauro Alcaraz (Universidad Autónoma de Madrid) -
7
Astrophysical Visible Neutrino Decay
Neutrino decay modifies neutrino propagation in a unique way; not only is there flavor changing as there is in neutrino oscillations, there is also energy transport from initial to final neutrinos. The most sensitive direct probe of neutrino decay is currently IceCube which can measure the energy and flavor of neutrinos traveling over extragalactic distances. For the first time we calculate the flavor transition probability for the cases of visible and invisible neutrino decay, including the effects of the expansion of the universe, and consider the implications for IceCube. As an example, we demonstrate how neutrino decay addresses a tension in the IceCube data.
Speaker: Dr Peter Denton (Brookhaven National Laboratory) -
5:15 PM
Coffee break
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8
Neutrino-Nucleus Interaction Physics with the Most Recent MINERvA Low-Energy Beam Data
MINERvA at FNAL is an experiment dedicated to the study of neutrino-nucleus interaction physics. Its goal is to provide constraints on nuclear effects that are crucial for present and future neutrino oscillation measurements, and to illustrate the interplay between hadronic and nuclear physics at the few-GeV regime. As the analysis of the Low-Energy data---the beam flux peaks at about 3 GeV with most of the rate between 1-6 GeV---is coming to a conclusion, nuclear effects are shown to be a complex phenomenon which challenges many of the popular theoretical descriptions. In this talk, a summary of the most recent MINERvA Low-Energy Beam results will be presented, alongside with discussions on their implication for future neutrino oscillation measurements.
Speaker: Dr Xianguo Lu (University of Oxford) -
9
Review of MINERvA's Medium Energy Neutrino Physics Program
The MINERvA experiment completed its physics run using the 6-GeV,on-axis NuMI ME beam at Fermilab. The experiment received a total of 12E20 protons on target in both neutrino and antineutrino mode running. This allows MINERvA a new level of statistical precision in neutrino interaction measurements with the ability to measure multi-dimensional differential cross sections. In order to make the most of this jump in statistics, a new level of precision in flux prediction has also been required. This talk will cover MINERvA’s Medium Energy (ME) physics program, including the new kinematic regimes that are now accessible, and will also discuss the exceptional precision reached in flux determination.
Speaker: Heidi Marie Schellman (Oregon State University (US)) -
10
Recent Cross-section Measurements from MicroBooNE
MicroBooNE is a liquid argon time projection chamber in the Booster Neutrino Beam at Fermilab. The large event rate and 3 mm wire spacing of the detector provide high-statistics, precise-resolution imaging of neutrino interactions leading to low-threshold, high-efficiency event reconstruction with full angular coverage. As such, MicroBooNE is an ideal place to probe neutrino-argon interactions in the hundreds-of-MeV to few-GeV energy range, and to study the impact of nuclear effects through detailed measurements of hadronic final states. This will be the subject of this talk.
Speaker: Raquel Castillo Fernandez (FNAL) -
11
Neutral Current Pi0 Rate Measurement with the MicroBooNE Detector
The talk presents the first measurement of Neutral Current (NC) $\pi^0$ production on argon in a sub-GeV neutrino beam with the MicroBooNE liquid argon time projection chamber (LArTPC) detector. The analysis qualifies data to Monte Carlo agreement in several reconstructed kinematic variables, and investigates contributions from coherent and non-coherent NC $\pi^0$ production processes independently. Those are the dominant contributing backgrounds to MicroBooNE’s search for low-energy excess single-photon events, for two separate exclusive final state samples. A data-driven determination of the NC $\pi^0$ rate and coherent fraction is critical for constraining backgrounds to MicroBooNE’s single-photon search.
Speaker: Mark Ross-Lonergan (Columbia University) -
12
Charged-Current Electron Neutrino measurement with the MicroBooNE detector
MicroBooNE is the first phase of Fermilab's Short Baseline Neutrino (SBN) Liquid Argon Time Projection Chamber (LArTPC) programme.
This talk outlays the first characterisation of electron neutrinos in a muon neutrino beam with the LArTPC detector technology. The Booster Neutrino Beam has an energy peaking around 1 GeV and an electron content of approximately 0.5%. The analysis investigates electrons produced in charged-current electron neutrino interactions. The kinematics of the electrons are measured along with comparisons to simulation. Most of the systematic uncertainties are constrained using a data-driven sample of charged-current muon neutrino events. The measurement of electron neutrinos originating from the Booster Neutrino Beam is a crucial component to understand the nature of the observed excess of low energy electromagnetic-like events at MiniBooNE.Speaker: Dr Wouter Van De Pontseele (Harvard University) -
13
Recent Cross-section Results from the T2K Experiment
One of the largest systematic uncertainties affecting neutrino oscillation measurement comes from present limited knowledge of (anti-)neutrino-nucleus interactions. Neutrino scattering understanding is crucial for the interpretation of neutrino oscillation since it affects background estimation and neutrino energy reconstruction. Thus, precise (anti-)neutrino-nucleus cross section measurements are vital for the present and future long-baseline neutrino oscillation experiments. The T2K long-baseline neutrino oscillation experiment, in addition to its contributions to neutrino oscillation measurement, has a wide program of neutrino interaction cross-section measurements using its near detector complex. With multiple targets (carbon, water, argon, iron), and with on- and off-axis detectors which sample different neutrino spectra from the same beamline, T2K is able to investigate atomic number and energy dependent behavior in a single experiment. In this talk an overview of the T2K neutrino cross sections, focusing on the latest results is presented.
Speaker: Dr Ka Ming Tsui (University of Liverpool) -
14
Neutrino Oscillations Results from the T2K Experiment
The T2K experiment probes the masses and mixing of neutrinos through measurements of neutrino oscillations. A beam of muon neutrinos or muon antineutrinos is generated at the J-PARC proton accelerator on the east coast of Japan, and the beam’s composition is measured 295 km away in the Super-Kamiokande detector. The transition of muon neutrinos and antineutrinos to other flavors and the appearance of electron neutrinos and antineutrinos are governed by neutrino mixing and mass parameters, including the phase $\delta_{cp}$, which determines the amount of CP violation in neutrino mixing. Previous measurements from T2K have shown a strong constraint on $\delta_{cp}$ with the exclusion of a significant fraction of $\delta_{cp}$ values at 3$\sigma$ confidence. Here, we present the latest results from T2K with data collected through 2020 and the prospects for more sensitive measurements by T2K in the future.
Speaker: Laura-Iuliana Munteanu (Université Paris-Saclay (FR)) -
15
The T2K ND280 Upgrade
In view of the J-PARC program of upgrades of the beam intensity, the T2K collaboration is preparing towards an increase of the exposure aimed at establishing leptonic CP violation at 3 $\sigma$ level for a significant fraction of the possible $\delta_{CP}$ values. To reach this goal, an upgrade of the T2K near detector ND280 will be installed at J-PARC in 2021, with the aim of reducing the overall statistical and systematic uncertainties at the appropriate level of better than 4\%.
We have developed an innovative concept for this neutrino detection system, comprising the totally active Super-Fine-Grained-Detector (SuperFGD), two High Angle TPC (HA-TPC) and six TOF planes.
The SuperFGD, a highly segmented scintillator detector, acting as a fully active target for the neutrino interactions, is a novel device with dimensions of ~2x1.8x0.6 m3 and a total mass of about 2 tons. It consists of about 2 millions of small scintillator cubes each of 1 cm3. Each cube is covered by a chemical reflector. The signal readout from each cube is provided by wavelength shifting fibers inserted connected to micro-pixel avalanche photodiodes MPPCs. The total number of channels will be ~60,000. We have demonstrated that this detector, providing three 2D projections, has excellent PID, timing and tracking performance, including a $4 \pi$ angular acceptance, especially important for short proton and pion tracks.
The HA-TPC will be used for 3D track reconstruction, momentum measurement and particle identification. These TPC, with overall dimensions of 2x2x0.8 m3, will be equipped with 32 resistive Micromegas. The thin field cage (3 cm thickness, 4% rad. length) will be realized with laminated panels of Aramid and honeycomb covered with a kapton foil with copper strips. The 34x42 cm2 resistive bulk Micromegas will use a 500 kOhm/square DLC foil to spread the charge over the pad plane, each pad being appr. 1 cm2. The front-end cards, based on the AFTER chip, will be mounted on the back of the Micromegas and parallel to its plane.
The time-of-flight (TOF) detector will allow to reject events generated in the passive areas of the detector and improve particle identification. The TOF will consist of 6 planes with about 5 m2 surface area surrounding the SuperFGD and the TPCs. Each plane will be assembled with 2.2 m long cast plastic scintillator bars with light collected by arrays of large-area MPPCs from two ends. The time resolution at the bar centre is 150 ps.
In this talk we will report on the design of these detectors, their performance, the results of the test beam and the plan for the construction.Speaker: Davide Sgalaberna (ETH Zurich (CH)) -
16
Latest Oscillation Results Combining Neutrino and Antineutrino Data from the NOvA Experiment
The NOvA experiment is a long-baseline neutrino oscillation experiment that uses the NuMI beam from Fermilab to detect both electron and muon flavored neutrinos in a Near Detector, located at Fermilab, and a Far Detector, located at Ash River, Minnesota. NOvA's primary physics goals include precision measurements of neutrino oscillation parameters, such as $\theta_{23}$ and the atmospheric mass-squared splitting, along with probes of the mass hierarchy and the CP violating phase. This talk will present the latest NOvA results using a combined neutrino and anti-neutrino dataset based on a beam exposure of approximately $13 \times 10^{20}$ protons-on-target in each dataset.
Speaker: Michael Baird (University of Virginia) -
17
The NOvA Test Beam Program
NOvA is a long-baseline oscillation neutrino experiment designed to study and measure a wide range of important topics for neutrino physics such as the neutrino mixing parameters, the neutrino mass hierarchy, and CP violation in the lepton sector. The NOvA Test Beam experiment uses a scaled-down detector of 30 tons to analyze tagged beamline particles. A new tertiary beamline deployed at Fermilab can select and identify electrons, muons, pions,kaons and protons with energies from 0.3 to 2 GeV. Using these data, the Test Beam program will provide NOvA with a better understanding of the largest systematic uncertainties impacting NOvA’s analyses, which include the detector response, calibration, and hadronic and electromagnetic energy resolution. In this talk, I will present the status
and future plans for the NOvA Test beam program, along with preliminary results.Speaker: Michael Wallbank -
18
The COHERENT Experiment at the Spallation Neutron Source
The pioneering experiments by the COHERENT collaboration at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory yielded the first observations of coherent elastic neutrino nuclear scattering (CEvNS). The first observation on argon was recently presented and demonstrates the potential of this new neutrino laboratory to exploit CEvNS as a new probe of physics topics including electromagnetic properties, searches for physics beyond the standard model, and nuclear form factors. COHERENT is deploying two new instruments to measure CEvNS on sodium and germanium nuclei and is pursuing multiple ton-scale detectors to improve precision and accuracy. The SNS is also ideally suited for a broader set of high-precision neutrino physics measurements and dark matter searches because of the accelerator's intensity, pulsed-structure, and proton beam energy. The experimental features of this new capability as well as the recent results of our operating detectors will be presented.
Speaker: Alexey Konovalov -
19
Sterile neutrino searches with the ICARUS detector
The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratories studying neutrino oscillations with the CNGS neutrino beam from CERN, and searching for atmospheric neutrino interactions. ICARUS performed a sensitive search for LSND-like anomalous $\nu_e$ appearance in the CNGS beam, which contributed to the constraints on the allowed parameters to a narrow region around 1 eV$^2$, where all the experimental results can be coherently accommodated at 90% C.L. After a significant overhauling at CERN, the T600 detector has now been placed in its experimental hall at Fermilab where installation activities are in progress. It will be soon exposed to the Booster Neutrino Beam to search for a sterile neutrino within the Short Baseline Neutrino (SBN) program, devoted to definitively clarify the open questions of the presently observed neutrino anomalies. The proposed contribution will address ICARUS achievements, its status and plans for the new run at Fermilab and the ongoing developments of the analysis tools needed to fulfill its physics program.
Speaker: Christian Farnese (Universita e INFN, Padova (IT)) -
20
Search for a Low-energy Excess with MicroBooNE
MicroBooNE is a neutrino experiment based at Fermilab that utilizes a liquid argon time projection chamber (LArTPC) located on-axis in the Booster Neutrino Beam (BNB) at Fermilab. One of the experiment’s main goals is to search for excess low-energy electromagnetic-like events as seen by the MiniBooNE experiment, located just downstream of MicroBooNE in the BNB. This talk will present MicroBooNE's low-energy excess search, including targeted searches for both single-photon-like and single-electron-like events.
Speaker: David Caratelli (Fermi National Accelerator Laboratory) -
21
Search for heavy neutral lepton production at the NA62 experiment
Searches for heavy neutral lepton production in K+ --> e+N and K+ --> mu+N decays using the data set collected by the NA62 experiment at CERN in 2016-18 are presented. Upper limits on the elements of the extended neutrino mixing matrix $|U_{e4}|^2$ and $|U_{\mu4}|^2$ are established at the levels of $10^{-9}$ and $10^{-8}$, respectively, improving on the earlier searches for heavy neutral lepton production and decays in the kinematically accessible mass range.
Speaker: Evgueni Goudzovski
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1
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Beyond the Standard Model: Session I - PremiereConveners: Alexandre Sousa (University of Cincinnati), Mia Tosi (Università degli Studi di Padova & INFN)
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22
R-parity violating SUSY searches in ATLAS
R-parity violating (RPV) SUSY models evade the stringent limits from missing-energy-based searches, and remain excellent candidates for low-scale SUSY. ATLAS has completed several dedicated searches for RPV signatures in Run 2, the most recent of which will be shown in this talk.
Speaker: Johannes Josef Junggeburth (Max-Planck-Institut fur Physik (DE)) -
23
New bounds on sneutrino masses through collider searches
Though collider searches are constraining supersymmetric parameter space, generic model independent bounds on sneutrinos remain very low. We calculate new model independent lower bounds on general supersymmetric scenarios with sneutrino LSP and NLSPs. By recasting ATLAS LHC exotic searches in mono boson channels, we place an upper bound on the cross section on $pp \rightarrow \tilde{\nu} \tilde{\nu} + V $ processes in mono-photon, mono-$Z$ and mono-Higgs channels. We also evaluate the LHC discovery potential of sneutrinos in the HL-LHC 3 inverse attobarn run.
Speaker: Humberto Gilmer (Ohio State University) -
24
Higgs properties: constraints and sensitivity on Supersymmetry?
We present some highlights on the complementarity of the Higgs and SUSY searches at the LHC, using the 8 and 13 TeV results. In particular, we discuss the constraints that can be obtained on the MSSM parameters by the determination of the Higgs boson mass and couplings. In addition, we investigate the interplay with heavy Higgs searches, and evaluate how higher LHC luminosities and a future linear collider can help probing the pMSSM Higgs sector and reconstructing the underlying parameters.
Speaker: Nazila Mahmoudi (Universite Claude Bernard Lyon I (FR)) -
25
Sbottoms as probes to MSSM with nonholomorphic soft interactions
Presence of non-holomorphic soft SUSY breaking terms is known to be a possibility in the popular setup of the Minimal Supersymmetric Standard Model (MSSM). It has been shown that such a scenario known as Non-Holomorphic Supersymmetric Standard Model (NHSSM) could remain ‘natural’ (i.e., not fine-tuned) even in the presence of a rather heavy higgsino-like LSP. In a first study of such a scenario at colliders (LHC), we explore a possible way that focuses on the sbottom phenomenology. This exploits the usual tanβ-dependence (enhancement) of the bottom Yukawa coupling but reinforced/altered in the presence of non-vanishing nonholomorphic soft trilinear parameter A'_b. For a given set of masses of the sbottom(s) and the light electroweakinos (LSP, lighter chargino etc.) which are known from experiments, the NHSSM could manifest itself via event rate in the 2b + MET final state, which could be characteristically different from its MSSM expectation. Impact on the phenomenology of the stops at the LHC is also touched upon.
Speaker: Ms Samadrita Mukherjee (Indian Association for the Cultivation of Science) -
26
Beyond the Standard Model Physics Prospects at Deep Underground Neutrino Experiment
The Deep Underground Neutrino Experiment (DUNE) is an international project for neutrino physics and proton-decay searches, currently in the design and planning stages. Once built, DUNE will consist of two detectors exposed to the world’s most intense neutrino beam. The near detector will record neutrino interactions near the beginning of the beamline, at Fermilab. The other, much larger, detector, comprising four 10-kton liquid argon time projection chambers (TPCs), will be installed at a depth of 1.5 km at the Sanford Underground Research Facility in South Dakota, about 1300 km away from the neutrino source.
The unique combination of the high-intensity neutrino beam with DUNE's high-resolution near detector system and massive LArTPC far detector enables a variety of probes of BSM physics, either novel or with unprecedented sensitivity, from the potential discovery of new particles (sterile neutrinos or dark matter), to precision tests of beyond the three-flavor mixing paradigm, Non-standard Neutrino Interactions, Heavy Neutral Leptons, or the detailed study of rare processes (e.g. neutrino trident production). The talk will review these physics topics and discuss the prospects for their discovery at the DUNE experiment.Speaker: Doojin Kim (University of Florida) -
27
Search for Proton Decay via $p\to e^+\pi^0$ and $p\to \mu^+\pi^0$ in 450 kiloton$\cdot$years Exposure of the Super-Kamiokande Detector
Super-Kamiokande is a 50 kton water Cherenkov detector in Japan. One of the main physics goals is to test Grand Unified Theory by searching for proton decay. The $p\to e^+\pi^0$ and $p\to \mu^+\pi^0$ decay modes are the most prospective because they are predicted in many theories, and because of their unique event topologies, signal and atmospheric neutrino background events that can be clearly discriminated experimentally. Super-Kamiokande has been operating from April 1996 and accumulated a large amount of data with a great potential for discovery. In order to further improve the search sensitivity, we have enlarged the fiducial mass of the Super-Kamiokande detector by 20% and added 25% more exposure by livetime update since the last published results in 2017, resulting in 1.5 times larger statistics. In this talk, the latest proton decay search results, especially via $p\to e^+\pi^0$ and $p\to \mu^+\pi^0$ modes with the larger fiducial mass will be presented.
Speaker: Akira Takenaka (University of Tokyo) -
28
Search for heavy neutral leptons decaying into muon-pion pairs in the MicroBooNE detector
We will present upper limits on the production of heavy neutral leptons (HNLs) decaying to muon-pion pairs using data collected with the MicroBooNE liquid-argon time projection chamber (TPC) operating at Fermilab. This search is the first of its kind performed in a liquid-argon TPC and the first beyond the Standard Model result obtained with the MicroBooNE detector. We use data collected in 2017 and 2018 corresponding to an exposure of 2 x 1020 protons on target from the Fermilab Booster Neutrino Beam, which produces mainly muon neutrinos with an average energy of about 800 MeV. HNLs with higher mass are expected to have a longer time-of-flight to the liquid-argon TPC than Standard Model neutrinos. The data are therefore recorded with a dedicated trigger configured to detect HNL decays that occur after the neutrino spill reaches the detector. We set upper limits at the 90\% confidence level on the element U_mu2 of the extended PMNS mixing matrix in the range for Dirac HNLs and Majorana HNLs, assuming HNL masses between 260 and 385 MeV.
Speaker: Owen Robert Young Goodwin (University of Manchester (GB)) -
29
Explaining the SM flavor structure with grand unified theories
We do not know why there are three fermion families in the Standard Model (SM), nor can we explain the observed pattern of fermion masses and mixing angles. Standard grand unified theories based on the SU(5) and SO(10) groups fail to shed light on this issue, since they also contain three copies of fermion representations of an enlarged gauge group.
However, it does not need to be so. In this talk, I will discuss the possibility that the Standard Model families are distributed over distinct representations of a grand unified model, in which case the gauge symmetry itself might discriminate the various families and explain (at least partially) the flavor puzzle.
Speaker: Renato Fonseca (IPNP, Charles University, Prague) -
30
A new program of searches for baryon number violation via neutron conversions at ORNL and the ESS
Searches for free neutrons converting to anti-neutrons (|ΔB|=2) and/or sterile neutrons (|ΔB|=1) play a distinctive and complementary role in the worldwide program of baryon number violation searches. These searches provide an important test of a global symmetry that must be violated to create a baryon asymmetry in the universe, and offer a unique portal to a dark sector through these feeble interactions. An international collaboration has developed a staged program of searches for neutron conversions at Oak Ridge National Laboratory and the European Spallation Source, which will allow both precision searches and research and development for subsequent stages, culminating in an ultimate improvement in sensitivity of around three orders of magnitude compared with earlier work. We will outline this program and present results of the first-stage search for neutron conversions to sterile neutrons in large magnetic fields, suggested to explain the long-standing neutron lifetime anomaly.
Speaker: Leah Broussard (Oak Ridge National Laboratory) -
5:45 PM
Coffee Break
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31
Searching for new resonances in partially-hadronic states in ATLAS
Many extensions to the Standard Model predicts new particles decaying into two bosons (VV, VH, Vgamma) making these important signatures in the search for new physics. Searches for such diboson resonances have been performed in final states with different numbers of leptons, photons and jets where new jet substructure techniques to disentangle the hadronic decay products in highly boosted configuration are being used. This talk summarizes ATLAS searches for diboson resonances with LHC Run 2 data in semileptonic final states.
Speaker: Stefan Raimund Maschek -
32
Search for new phenomena in leptonic final states at CMS
Many new physics models, e.g., compositeness, extra dimensions, extended Higgs sectors, supersymmetric theories, and dark sector extensions, are expected to manifest themselves in the final states with leptons and photons. This talk presents searches in CMS for new phenomena in the final states that include leptons and photons, focusing on the recent results obtained using the full Run-II data-set collected at the LHC.
Speaker: Saranya Samik Ghosh (RWTH, III. Physik. Inst. A) -
33
Search for new physics with unconventional signatures at CMS
Many extensions to the standard model predict new particles and phenomena that may produce unique and unconventional signatures at the LHC. This talk presents results from searches that look for such unconventional signatures using novel reconstruction techniques in CMS with the full Run-II data-set collected at the LHC
Speaker: Brian Francis (The Ohio State Univ.) -
34
Search for new physics using final states with photons at CMS
Several theories of physics beyond the standard model predict new phenomena and interactions involving photons. This talk covers searches for new physics performed using data collected with the CMS detector at the LHC, which target final states consisting of photons.
Speaker: Justin Andrew Williams (The Univ. of Kansas) -
35
Searches for new heavy resonances in hadronic final states with the ATLAS detector
Many theories beyond the Standard Model predict new phenomena which decay to jets. These are of particular interest at the LHC since new phenomena produced in parton collisions are likely to produce final states with (at least) two partons. This talk presents the latest 13 TeV ATLAS results, covering exclusive searches for dijet resonances along with searches for dijet events produced in association with additional particles such as an additional isolated lepton, which overcomes the trigger limitations to extend to lower dijet masses.
Speaker: Jeremy Robert Love (Argonne National Laboratory (US)) -
36
Searches for vector-like quarks at CMS
We present results of searches for massive vector-like top and bottom quark partners using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. Single and pair production of vector-like quarks are studied, with decays into a variety of final states, containing top and bottom quarks, electroweak gauge and Higgs bosons. We search using several categories of reconstructed objects, from multi-leptonic to fully hadronic final states. We set exclusion limits on both the vector-like quark mass and cross sections, for combinations of the vector-like quark branching ratios.
Speaker: Julie Hogan (Brown Univ.) -
37
Fully Hadronic Diboson searches in ATLAS
Many extensions to the Standard Model predicts new particles decaying into two bosons (W, Z, photon, or Higgs bosons) making these important signatures in the search for new physics. Searches for such diboson resonances have been performed in different final states and new jet substructure techniques to disentangle the hadronic decay products in highly boosted configuration are being used. Novel analysis techinques, unsupervised learning, are also used to extract new feature from the data. This talk summarizes recent ATLAS diboson searches with LHC Run 2 data in fully hadronic final state.
Speaker: Steven Schramm (Universite de Geneve (CH)) -
38
Search for new new phenomena using jets at CMS
Many new physics models, e.g., compositeness, extra dimensions, extended Higgs sectors, supersymmetric theories, and dark sector extensions, are expected to manifest themselves in the final states with hadronic jets. This talk presents searches in CMS for new phenomena in the final states that include jets, focusing on the recent results obtained using the full Run-II data-set collected at the LHC.
Speaker: Dimitrios Karasavvas (Univ. of Athens) -
39
Search for millicharged particles at the LHC with the milliQan prototype
In this talk, I will present the results of a recent search for fractionally charged particles using a data sample of proton-proton collisions provided by the CERN Large Hadron Collider in 2018. This search was carried out with a prototype scintillator-based detector, which allows the first sensitivity to particles with charges ≤0.1e at a hadron collider. The existence of new particles with masses between 20 and 4700 MeV is excluded at 95% confidence level for charges between 0.006e and 0.3e, depending on their mass. New sensitivity is achieved for masses larger than 700 MeV. I will discuss the concept of the experiment, the results of the search, and the plan for the full milliQan detector given the successful operation of the prototype.
Speaker: Matthew Daniel Citron (Univ. of California Santa Barbara (US)) -
40
Search for non-Newtonian gravity with optically-levitated microspheres
The universal law of gravitation has undergone stringent tests for many decades over a significant range of length scales, from atomic to planetary. Of particular interest is the short distance regime, where modifications to Newtonian gravity may arise from axion-like particles or extra dimensions. We have constructed an ultra-sensitive force sensor based on optically-levitated microspheres with a force sensitivity of $10^{-17}$ N/$\sqrt{\rm Hz}$ for the purpose of investigating non-Newtonian forces in the 1-100 $\mu$m range. Microspheres interact with a variable-density attractor mass made by alternating silicon and gold segments with periodicity of 50 $\mu$m. The attractor can be located as close as 10 $\mu$m from a microsphere. I describe the characterization of this system, its sensitivity, and some preliminary results. Further technological developments to reduce background are expected to provide orders of magnitude improvement in the sensitivity, probing beyond current constraints on non-Newtonian interactions.
Speaker: Dr Nadav Priel (Stanford University)
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22
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Top Quark and Electroweak Physics: Session I - PremiereConveners: Aram Apyan (Fermi National Accelerator Lab. (US)), Maria Aldaya Martin (DESY), Jiri Kvita (Palacky University (CZ)), Tomas Jezo (University of Zurich)
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41
Recent measurements of electroweak boson properties at D0
We present a measurement of the shape of the transverse momentum distribution for W boson in the $W \to e\nu$ decay channel using 4.3 fb$^{-1}$ of $ p\bar p$ data at $\sqrt s=$1.96 TeV. The results are compared to QCD predictions both at reconstructed and particle level. We also present a measurement of the shape of the Z boson rapidity using $Z/\gamma^{*} \to\mu^+\mu^- $ events produced in 8.6 fb$^{-1}$ of $ p\bar p$ data. This measurement is compared to NNLO QCD predictions using different sets of parton density functions.
Speaker: Chen Wang (University of Science and Technology of China (CN)) -
42
W boson measurements with the CMS experiment
Latest results on W boson measurements are presented using collision data collected by CMS. Multi-differential production cross sections, charge asymmetry, polarization measurements will be discussed, and new other results.
Speaker: Riccardo Salvatico (Univ. di Torino e Sez. dell'INFN) -
43
Electroweak and Top Physics in the Forward Region
The LHCb detector at the LHC offers unique coverage of forward rapidities, allowing the experiment to play an important role in measurements of Standard Model processes at the LHC. Measurements of W, Z, top and jet production at LHCb will be presented, and future prospects will be discussed.
Speaker: Lorenzo Sestini (Universita e INFN, Padova (IT)) -
4:45 PM
General discussion
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4:55 PM
Coffee Break
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44
Recent ttbar and single top inclusive cross sections results in CMS
Latest results on inclusive top quark pair and single top quark production cross sections are presented using collision data collected by CMS. The single top quark analyses investigate separately the production of top quarks via t-channel exchange, via associated production with a W boson (tW), and via the s-channel.
Speaker: Denise Muller (KIT - Karlsruhe Institute of Technology (DE)) -
45
Measurements of differential cross-sections of top-quark-antiquark pair-production with the ATLAS detector
Comprehensive measurements of differential cross-sections of top-quark-antiquark pair-production are presented. The measurements are performed in the electron-muon, the lepton+jets and the all-hadronic channels. The latter two allow for reconstruction of the top-quark and top-quark-pair kinematic distributions. In the electron-muon channel, kinematic properties of the two leptons are measured differentially. High sensitivity of some distributions to PDFs is demonstrated. The lepton+jets and all-hadronic channels are complementary in terms of range and resolution for several top-quark variables. All three measurements use data recorded in the years 2015 and 2016 during Run 2 of the LHC. The measurements are compared quantitatively with predictions from several setups of next-to-leading order matrix-element generators combined with parton-shower generators and from fixd order calculations at NNLO in QCD. In addition, the total cross-section is measured in the electron-muon channel. A precision of 2.4 % is reached, well below the uncertainty of predictions at next-to-next-to-leading order in QCD. The total cross-section is compared to predictions by different sets of parton distribution functions and is used to determine the top-quark mass. A total cross-section measurement based on the full Run 2 dataset in the lepton+jets channel is also presented.
Speaker: Teng Jian Khoo (University of Innsbruck (AT)) -
46
Top quark pair and single top differential cross sections in CMS
Differential measurements of top quark pair and single top quark production cross sections are presented using data collected by CMS. The cross sections are measured as a function of various kinematic observables of the top quarks and the jets and leptons of the event final state. The results are confronted with precise theory calculations.
Speaker: Georgios Bakas (National Technical University of Athens) -
6:35 PM
General discussion
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6:45 PM
Coffee Break
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47
KKMC-hh for Precision EW Phenomenology at the LHC
We describe the program KKMC-hh, which calculates Z boson processes in hadronic collisions using coherent exclusive exponentiation (CEEX) with exact second-order photonic corrections at next-to-leading log and first-order weak vertex corrections, including initial and final state photonic radiation and initial-final interference. We describe current applications to precision forward-backward asymmetry calculations for the measurement of the Weinberg angle at the LHC and upgrades in progress for use with an NLO QCD shower.
Speaker: Scott Alan Yost (The Citadel - The Military College of South Carolina (US)) -
48
Electroweak and QCD aspects in V+jets in CMS
The study of the associated production of vector bosons and jets constitutes an excellent testbench to check numerous QCD predictions. Total and differential cross sections of vector bosons produced in association with jets have been studied in pp collisions at 7, 8 and 13 TeV center-of-mass energies. Differential distributions as function of a broad range of kinematical observables are measured and compared with theoretical predictions. Final states with a vector boson and jets can be also used to study electroweak initiated processes, such as the vector boson fusion production of a Z or W boson that are accompanied by a pair of energetic jets with large invariant mass.
Speaker: Sarah Malik (Imperial College, Univ. of London) -
49
Improving Electroweak Precision Observables Including m_W, Γ_W, A_LR and TGCs with the ILD Detector
We discuss the improvements that the ILC can make in precision electroweak observables based on studies with the ILD detector concept. These include observables from WW production and radiative return to the Z at a centre of mass energy of 250 GeV, and from a dedicated stage of running at the Z pole. These improvements take advantage of the ILC capabilities for polarized electron and positron beams, and an accelerator design that accommodates data-taking at a wide range of beam energies. We also present new results on precision measurements of fermion pair production. The studies include experimental considerations evaluated in the context of the ILD detector concept and discussion of experimental strategies targeted at controlling relevant systematic uncertainties.
Speaker: Graham Wilson (The University of Kansas (US)) -
8:20 PM
General discussion
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8:30 PM
Discussion session: Top quark production
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41
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Quark and Lepton Flavour Physics: Session I - PremiereConveners: Ruth Van de Water (Fermilab), Karim Massri (CERN), Carla Gobel Burlamaqui De Mello (Pontificia Universidade Catolica (BR))
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50
Purely Leptonic Rare decays at LHCb
During Run 1 and 2 of the LHC, the LHCb experiment has collected large samples of beauty-hadron decays corresponding to an integrated luminosity of 9/fb at pp centre-of-mass energy of 7, 8 and 13 TeV. Very rare decays are discussed, with an emphasis on Flavour-Changing Neutral-Current processes of the type $B^0_{(s)} \to l^+ l^-$. Anomalies in the branching fractions of these decays are also discussed and connected with tests of Lepton-Flavour-Universality.
Speaker: Lauren Emma Yeomans (University of Liverpool (GB)) -
51
Search for New Physics with rare decays at CMS
Recent CMS results are reported either for the observation of the B0s to mu+mu- decay and for the search of the B0 to mu+mu- decay by adding the 2016 13TeV data to the Run-I data and for the search of the tau to 3 muons decay, with 2016 13 TeV data, by considering tau leptons coming both from Ds and W decays.
Speaker: Ozlem Ozcelik Ozludil (Bogaziçi Univ., Dept of Physics) -
52
ATLAS results on Heavy Flavour production and decay (including rare processes)
The heavy flavour production and decays are studied with the ATLAS detector, mainly through final states containing muons. This talk will summarise recent results from ATLAS, including measurements on Bc mesons decaying in different final states and of Ds cross-sections. The latest results on the studies of rare processes are also presented. Particular attention will be given to Flavour Changing Neutral Current processes, such as the decay of Bs and B0 into two muons.
Speaker: Sally Seidel (University of New Mexico / ATLAS) -
53
Study of $B$ and $B_{s}$ Decays at Belle
We present the study of $B_{s}$ decays using 121.4 fb$^{-1}$ of data collected at $\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric-energy electron-positron collider. We search for $B_{s}\to \eta^{\prime} \eta$ and $B_{s}\to \eta^{\prime} K^{0}_{S}$, which are suppressed in the standard model (SM) and can receive contribution of physics beyond the SM. We also report the first model-independent measurement of B($B_{s}\to D_{s} X$) using $B_{s}$ semileptonic tagging; this is necessary for measuring absolute rates and branching fractions of other $B_{s}$ decays. In addition, we present precise measurements of the branching fraction and CP asymmetry in $B\to \phi \phi K$ decays using Belle data that corresponds to 772 million $B\overline{B}$ pairs. These decays are mediated by the $b\to s$ FCNC transition, where one can observe large CP violation due to interference of potential new-physics amplitudes appearing in the loop with the $b\to c$ tree-level transition of $B\to \eta_{c} K$, $\eta_{c}\to \phi \phi$.
Speaker: Nisar Nellikunnummel (BNL) -
54
Rare B-decay anomalies
Rare $B$-decays are among the most promising indirect probes for the search for New Physics. In recent years there have been several significant hints for physics beyond the SM in semileptonic $b\to s \ell \ell$ transitions. Interestingly, the analysis of these so-called B anomalies indicate a consistent pattern of lepton flavour non-universality.
We present updated global fits of Wilson coefficients both when only one or two Wilson coefficients are involved as well as in a 20-dimensional fit. Using the new data of the LHCb angular analysis of the $B\to K^* \mu^+ \mu−$ decay we make statistical comparisons to determine whether the most favoured explanation of the anomalies is New Physics or underestimated hadronic effects.Speaker: Siavash Neshatpour -
55
Rare charm decays at LHCb
LHCb is playing a crucial role in the study of rare and forbidden decays of charm hadrons, which might reveal effects beyond the Standard Model. We present the latest searches for, and measurements using, rare charm decay processes with two leptons in the final state.
Speaker: Chris Burr (CERN) -
56
Radiative and Rare Charm Decays at BESIII
In this talk, we present the latest result on radiative and rare/forbidden decays for D mesons at the BESIII experiment based on 2.92 fb-1 and 3.19 fb-1 data taken at the center-of-mass energy 3.773 4.178 GeV with the BESIII detector, respectively. Based the data at 4.178 GeV, a search for the rare radiative leptonic decay Ds->gamma e+ nu is performed for the first time with negative result and an upper limit (UL) of the branching fraction(BF) is set to be less than 1.310E-4 at 90\% confidence level (CL). With this data sample, we also search for the rare decay Ds-> p bar e+ nu. No significant signal is observed, and an UL B(Ds -> p pbar e+ nu)<2.010E-4 is determined at the 90\% CL. Using the dataset at 3.773 GeV, we search for rare decays of D-> h(h’)e+e- with double tag method, where h(‘) are hadrons. No significant excess over the expected backgrounds is observed, the ULs on the signal BFs at the 90\% CL are determined. For the D+ decays, the searches are performed for the first time, while for D0 decays, the ULs are improved in general by a factor of 10, compared to previous measurements. All the ULs on the BF, at the level of $10E-5~10E-6, are above the SM predictions, which include both LD and SD contributions. Also, we search for the Majorana neutrino in the lepton number violating (LNV) decays $D\to K pi e+e-. No significant signal is observed, and the ULs on the BF at the 90\% CL are set to be less than few $10E-6. The Majorana neutrino is searched for with different mass assumptions ranging from 0.25 to 1.0 GeV/ in the decays D0 -> K- e+ nu_N(pi- e+) and D+->KS e+ nu_N(pi-e+), and the UL on the BF at the 90\% CL are extracted to be at the level of $10E-7~10E-6. The constraints on the mixing matrix element |V_{eN}|^2 are also evaluated.
Speaker: Dr Bo Zheng (University of South China) -
57
Rare and forbidden decays of D0 meson
We report the observation of the rare charm decay $D^0\to K^-\pi^+e^+e^-$, a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type $D^0\to h^- h^{'-} \ell^+ \ell^{'+}$, and $D^0\to h^- h^{'+} \ell^+ \ell^{'-}$, and a search for seven lepton-number-violating decays of the type $D^{0}\rightarrow X^{0} e^{\pm} \mu^{\mp}$, where $h$ and $h^{\prime}$ represent a $K$ or $\pi$ meson, $\ell$ and $\ell^{\prime}$ an electron or muon, and $X^{0}$ a $\pi^0$, $K^0_S$, $K^{*0}$, $\rho^{0}$, $\phi$, $\omega$, or $\eta$ meson. The results are based on $468$ fb$^{-1}$ of $e^+e^-$ collision data collected at or close to the $\Upsilon(4S)$ resonance with the $BABAR$ detector at the SLAC National Accelerator Laboratory.
Speaker: Racha Cheaib (University of British Columbia) -
5:30 PM
Coffee break
virtual coffee served
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58
Recent gems from kaon and their repercussions for future directions
Kaons have played a crucial role in Particle Physics from their early history including some profound discoveries. In this talk I will give account of recent progress on several challenging issues that have been with us for a long time. Seen in the light of this progress what can we learn from many of the flavor anomalies of the past many years will also be discussed.
Speaker: Amarjit Soni (Amarjit) -
59
Search for New Physics via the $K_L \to \pi^0 \nu \bar{\nu}$ decay at the J-PARC KOTO experiment
The purpose of the KOTO experiment, being conducted at J-PARC (Ibaraki Japan), is to search for New Physics
via the rare decay $K_L\rightarrow \pi^0 \nu \bar{\nu}$ using the high intensity $K_L$ beam provided by
the 30~GeV proton synchrotron.
The $K_L\rightarrow \pi^0 \nu \bar{\nu}$ decay is suppressed in the standard model, and
its observation may reveal hints of new physics.
The signature of $K_L\rightarrow \pi^0 \nu \bar{\nu}$ is two $\gamma$'s from a $\pi^0$ and
no other particles in the detectors surrounding the decay region.For the data collected between 2016 and 2018, a blind analysis technique was adopted to avoid
human bias in the determination of the selection criteria.
We unblineded the signal region in the summer of 2019, and observed candidate events.
Since then, we have been checking our software and hardware, and possibilities of backgrounds that we might have missed.
In this presentation, we report the progress in the analysis and the obtained feedback from the data taken in 2019 and 2020.Speaker: Dr Nobuhiro Shimizu (Osaka University) -
60
New result on the search for the $K^+ \to \pi^+ \nu\bar\nu$ decay at the NA62 experiment at CERN
The ultra-rare K+ —> pi+nunu decay benefits from a precisely predicted branching ratio in the SM (8.4 +- 1.0) x 10^{-11}, being almost free from theoretical uncertainties, and most importantly from a very high sensitivity to a variety of beyond-the-standard-model scenarios, making it one of the best candidates to reveal indirect effects of new physics in the flavour sector.
The NA62 experiment at the CERN SPS, designed to measure the branching ratio of K+ —> pi+ nunu with a decay-in-flight technique, collected data in 2016-2018. New results from the analysis of 2018 data, the largest data set so far collected, will be presented. The result will represent the most accurate measurement so far achieved of this ultra-rare decay.
Future prospects and plans for data taking from 2021 will also be presented.Speaker: Radoslav Marchevski -
61
New measurement of the $K^+\to\pi^+\mu^+\mu^-$ decay at NA62
The flavour-changing neutral current decay $K^+\to\pi^+\mu^+\mu^-$ is induced at the one-loop level in the Standard Model, and is well suited to explore its structure and, possibly, its extensions. The NA62 experiment took data in 2016--2018 with the main goal of measuring the $K^+\to\pi^+\nu\bar\nu$ decay. A scaled down di-muon trigger chain was operating along with the main trigger during the whole data taking period resulting in a large sample of about $3 \times 10^{12}$ kaon decays in the fiducial volume recorded using the di-muon trigger. New results from an analysis of the $K^+\to\pi^+\mu^+\mu^-$ decay using this sample will be presented.
Speaker: Lubos Bician (CERN) -
62
Latest results on rare kaon decays from the NA48/2 experiment at CERN
The NA48/2 experiment at CERN reports the first observation of the K± → π± π0 e+ e− decay from an exposure of 1.7×10^11 charged kaon decays recorded in 2003−2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region. The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated.
The most precise measurement of the charged kaon semi-leptonic form factors obtained by NA48/2 with 4.4 million Ke3 and 2.3 million Kmu3 events collected in 2004 will also be presented.Speaker: Mauro Raggi (LNF INFN) -
63
Latest D0 results on exotic hadrons produced in $p\bar p $ collision
We selected candidate events for production of the exotic charged charmonium-like states $Z_c^{\pm}(3900)$ decaying to $ J/\psi\pi^{\pm}$ and $X(3872)$ decaying to $J/\psi\pi^{\pm}\pi^{\mp}$. We use 10.4 $\rm fb^{−1}$ of $p\bar p$ collisions recorded by the D0 experiment at the Tevatron collider at $\sqrt s=$1.96 TeV. We measure the $Z_c$ mass and natural width using subsample of candidates originating from semi-inclusive weak decays of b-flavored hadrons and search for the $Z_c$ prompt production. We measure different production properties of the $X(3872)$, such as the prompt fraction as a function of the transverse momentum, that are compared to $\psi(2S)\to \psi\pi^{\pm}\pi^{\mp}$ production. The sample of 10.4 $\rm fb^{−1}$ is also used to search for the inclusive production of the pentaquark states observed in $pp$ collisions at LHCb, $P_c(4400)$ and $P_c(4457)$, decaying to $J/\psi p$.
Speaker: Alexey Drutskoy -
64
Search for QCD exotic states at CMS
Novel CMS results in searches for “old" and new quarkonium-like states will be discussed.
Speaker: Sergey Polikarpov (Moscow Eng. Phys. Inst.) -
7:22 PM
Coffee break
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65
Isospin amplitudes in b-baryon decays at LHCb
Ratios of isospin amplitudes in hadron decays are a useful probe of the interplay between weak and strong interactions, and allow searches for physics beyond the Standard Model. We present results on isospin amplitudes in b-baryon decays using proton-proton collision LHCb data collected at center-of-mass energies of 7, 8 and 13 TeV.
Speaker: Sheldon Stone (Syracuse University (US)) -
66
Production studies of double Bottomonia and of Bottomonium in association with an electroweak Boson at CMS
New CMS measurements of the Y(1S) pair production cross section at 13TeV and of the production of Y(nS) mesons in association with an electroweak boson will be discussed.
Speaker: Sheila Silva Do Amaral (Univ. Estado Rio de Janeiro) -
67
ATLAS results on quarkonia and associated production
The associated production of vector boson with quarkonia is a key observable for understanding the quarkonium production mechanisms, including the separation of single and double parton scattering components.
This talk will present the latest measurements from ATLAS on charmonium production at high transverse momentum, and the associated production of a W-boson with a J/psi meson.Speaker: Brad Abbott -
68
Hadronic charm meson decays at BESIII
BESIII has collected data samples corresponding to luminosities of 2.93 fb-1 and 3.19 fb-1 at center-of-mass energies of 3.773 and 4.178 GeV, respectively. The data set collected at 3.773 GeV contains quantum-correlated D0D0bar pairs that allow access to the phase differences between amplitudes. We report the measurements of strong phase differences in D0 decays, including KS/L pi+ pi-, which can reduce the gamma/phi3 measurement systematic uncertainty at LHCb and Belle II. In addition, we report the measurements of the absolute branching fractions and the amplitude analyses of D+, D0, and Ds decays.
Speaker: Chuangxin Lin (Sun Yat-Sen University) -
69
Recent charm results from Belle
Using the full data collected with the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider, we report the first measurement of charm-mixing $y_{CP}$ in $D^{0}$ decays to the CP-odd final state $K_{S}^{0} \omega$. We present a Dalitz-plot analysis of the three-body decay $D^{0}\to K^{-} \pi^{+} \eta$. Along with these, we present other results related to charm physics at Belle.
Speaker: Dr Longke Li (Univ. of Cincinnati) -
70
Production studies of D and B mesons at CMS
New CMS measurements of prompt D*+, D+ and D0 production cross sections at 13TeV are presented together with novel studies of the production of excited Bc states carried out with full Run-II data.
Speaker: Valentina Mariani (Univ. di Perugia e Sez. dell'INFN)
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50
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Strong Interactions and Hadron Physics: Session I - PremiereConveners: Radja Boughezal (Argonne National Laboratory), Laura Fabbietti (Technische Universitaet Muenchen (DE)), Sarka Todorova (Charles University (CZ))
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71
Jet production at NLO in the Parton Branching method
Transverse momentum dependent (TMD) parton distributions obtained from the Parton Branching (PB) method are combined with next-to-leading-order (NLO) calculations of jet production to obtain predictions for LHC jet final states. In addition, a new initial state Parton Shower, which is based on the TMD distributions, and final state Parton Showers are included together with hadronization. We compare our predictions with jet and Z+jet measurements performed at the LHC, finding good agreement. We present first results for multi-jet merging with PB-TMDs, illustrating the application of the method to differential jet rates and transverse momentum spectra.
Speaker: Armando Bermudez Martinez (CMS-DESY) -
72
Precision measurements of jet production at the ATLAS experiment
Measurements of jet production are sensitive to the strong coupling constant, high order perturbative calculations and parton distribution functions. In this talk, we present the most recent ATLAS measurements of jet production at 13 TeV. Depending on the availability of the results, we may show measurements of jet and multijet production as well as measurements sensitive to the strong coupling constant.
Speaker: Peter Loch (University of Arizona (US)) -
73
Jet measurements at CMS
Measurements of jet production in proton-proton collisions at the LHC are crucial for precise tests of QCD, improving the understanding of the proton structure and are important tool for searches for physics beyond the standard model. We present recent measurements of double-differential cross section of jet production at centre-of-mass energy of 13 TeV with 2016 data and compare them to various predictions. We also report studies on the impact of these measurements on the determination of the strong coupling and of parton density functions of the proton.
Speaker: Cristian Baldenegro Barrera (The Univ. of Kansas) -
74
Measurements of W/Z boson production in association with jets at ATLAS
Measurements of W/Z-boson production in association with jets provide important test of perturbative QCD prediction and also yield information about the parton distribution functions of the proton. In this talk, differential cross-sections for vector-boson production in association with jets using proton-proton collisions collected by the ATLAS experiment are presented. The data are corrected for detector inefficiency and resolution and compared to state-of-the-art theoretical predictions. The impact of the choice of parton distribution function is also presented.
Speaker: Camilla Vittori -
75
V+heavy flavor jets and constraints to PDFs in CMS
The associated production of vector bosons V (W, Z or gamma) and jets originating from heavy-flavour (c or b) quarks is a large background source in measurements of other standard model processes, Higgs boson studies, and many searches for physics beyond the SM. The study of events with a vector boson accompanied by heavy-flavour jets is crucial to refine the theoretical calculations in perturbative QCD, as well as to validate associated Monte Carlo predictions. Differential cross sections in V+ c/b jets are measured as a function of several kinematic observables with the CMS detector at 8 and 13 TeV. The study of the associated production of a vector boson with jets from a c-quark is especially interesting, as it allows to extract information on the proton parton density functions.
Speaker: Anton Stepennov (Inst. for Theoretical and Exp. Phys.) -
76
Heavy-flavour correlations, jets and multiplicity dependent studies on heavy-flavour hadrons in small systems with ALICE
In this contribution, the latest heavy-flavour results on the pp
and p--Pb data samples collected during the LHC Run 2 with ALICE at several center-of-mass energies will be presented.
A comprehensive study of the multiplicity dependent open heavy-flavour hadron production and quarkonium self-normalised yields in pp collisions at $\sqrt{s}$ = 13 TeV will be shown. Such measurements constitute a valuable tool to characterize Multi-Parton Interactions (MPI), as well as the interplay between hard and soft particle production mechanisms. In particular, these studies include $\psi$(2S) production at forward rapidity, while multiplicity dependent measurements at mid-rapidity will be discussed for D mesons, heavy-flavour decay electrons and inclusive J/$\psi$.
Moreover, the multiplicity dependent self-normalised yields of
heavy-flavour decay electrons at mid-rapidity, as well as $v_{2}$ measurements in high-multiplicity events for heavy-flavour decay muons at forward rapidity, will be discussed. Such studies aim to investigate possible collective effects in p—Pb collisions. In addition, measurements of heavy-flavor jet production and fragmentation and heavy-flavour correlations will be presented. These studies give direct access to the initial parton kinematics and allow us to characterize the heavy-quark fragmentation process, as well as to gain information on heavy-quark production mechanisms in pp collisions. Heavy-flavour jets studies are
extended to heavy-flavour hadron decay electrons and D-meson tagged charged jets measurements in pp and p--Pb collisions at $ \sqrt{s}=5.02$ and $13$ TeV and $\sqrt{s_{\rm NN}}=5.02$ TeV, respectively. The results of the jet-momentum fraction carried by the D meson at $\sqrt{s}=5.02$ and $13$ TeV and by the $\Lambda_{\rm c}$ baryon at $\sqrt{s}=13$ TeV will be discussed as well. The angular correlations of D-mesons and charged particles in pp and p--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV will be shown and comparison with model calculations will be discussed.Speaker: Marianna Mazzilli (Universita e INFN, Bari (IT)) -
77
HERA jet data in NNLO fits of HERAPDF and diffractive PDFs
NNLO predictions for jet production in Deep Inelastic Scattering have recently become available. These are used to extend the QCD HERAPDF2.0Jets fits, that were made to extract PDFs from inclusive HERA data and HERA jet data, from NLO to NNLO. In addition new jet data sets have become available since the publication of ERAPDF2.0 and these are also considered. A simultaneous fit to these data to extract PDFs and $\alpha_s$
results in a new NNLO determination of $\alpha_s(𝑀_Z)$.A new combined fit of diffractive parton distribution functions (DPDFs) to the H1 inclusive neutral-current and dijet production data in diffractive deep-inelastic scattering (DDIS) at next-to-next-to-leading order accuracy (NNLO) is presented. Compared to the previous HERA fits, the presented study includes the high-precision H1 HERA-II data, which represents 40 times higher luminosity for inclusive DDIS data sample and 6 times higher luminosity for the jet data, than previous studies by H1. In addition to the inclusive DDIS data at the nominal centre-of-mass energy $\sqrt{s} = 319$ GeV, also the inclusive data at 252 and 225 GeV are included into the fit. The inclusion of the most comprehensive dijet cross section data , together with their
NNLO predictions, provide enhanced constraints to the gluon component of the DPDF. The extracted DPDFs are compared to the alternative existing DPDFs at NLO accuracy, and are used to predict cross sections for a large number of the available dijet measurements.Speaker: Amanda Sarkar (University of Oxford (GB)) -
5:30 PM
Coffee break
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78
HERA data on azimuthal decorrelation and charged particle multiplicity spectra probing QCD dynamics and quantum entanglement effects
The azimuthal decorrelation angle between the leading jet and scattered lepton in deep inelastic scattering is studied with the ZEUS detector at HERA. The data was taken in the HERA II data-taking period and corresponds to an integrated luminosity of 330 pb${}^{−1}$. Azimuthal angular decorrelation has been proposed to study the
$Q^2$ dependence of the evolution of the transverse momentum distributions (TMDs) and understand the small-x region, providing unique insight to nucleon structure. Previous decorrelation measurements of two jets have been performed in proton-proton collisions at very high transverse momentum; these measurements are well described by perturbative QCD at next-to-leading order. The azimuthal decorrelation angle obtained in these
studies shows good agreement with predictions from Monte Carlo models including leading order matrix elements and parton showers.New experimental data on charged particle multiplicity distributions are presented, covering the kinematic ranges in momentum transfer $5 < Q^2 < 100$ GeV${}^{2}$ and inelasticity $0.0375 < y < 0.6$. The data were recorded with the H1 experiment at the HERA collider in positron-proton collisions at a centre-of-mass energy of 320 GeV. Charged particles are counted with transverse momenta $P_T > 150$ MeV and pseudorapidity $−1.6 < \eta_{lab} < 1.6$ in the laboratory frame, corresponding to high acceptance in the current hemisphere of the hadronic centre-of-mass frame. Charged particle multiplicities are reported on a two-dimensional grid of $Q^2$, y and on a three-dimensional grid of $Q^2$, y, η. The observable is the probability P(N) to observe N particles in the given $\eta$ region. The data are confronted with predictions from Monte Carlo generators, and with a simplistic model based on quantum entanglement and strict parton-hadron duality.
Speakers: Dr Zhoudunming Tu (BNL), Zhoudunming Tu (BNL) -
79
Precision measurements of single vector boson production at ATLAS
Precision measurements of the production cross-sections of W/Z boson at LHC provide important tests of perturbative QCD and information about the parton distribution functions for quarks within the proton. In this talk, we present fiducial and differential cross sections for inclusive W+, W− and Z boson production using data collected by the ATLAS experiment at center-of-mass energies of 2.76 TeV, 8 TeV and 13 TeV. The measurements are corrected for detector inefficiency and resolution and compared with state-of-the-art theoretical calculations.
Speaker: Kristin Lohwasser (University of Sheffield (GB)) -
80
Role of IR-Improvement in LHC/FCC Physics
One may use amplitude-based resummation in QED X QCD to achieve IR-improvement of unintegrable singularites in the infrared regime to arbitrary precision in principle. We illustrate such improvement in specific examples in precision LHC/FCC physics.
Speaker: Bennie Ward (Baylor University (US)) -
81
Precision QCD at the LHeC and the FCC-eh
The LHeC and the FCC-eh are the cleanest, high resolution microscopes that the world can build in the nearer future. Through a combination of neutral and charged currents and heavy quark tagging, they will unfold the parton structure of the proton with full flavour decomposition and unprecedented precision. In this talk we will present the most recent studies on the determination of proton parton densities as contained in 2020 White Paper on the LHeC. We will also demonstrate the prospects for a per mille accuracy determination of the strong coupling constant, both through scaling violations in inclusive DIS and jet production, as well as their combination.
Speaker: Claire Gwenlan (University of Oxford (GB)) -
7:00 PM
Coffee break
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82
Soft-gluon effective coupling
We consider the extension of the CMW soft-gluon effective coupling in the context of soft-gluon resummation for QCD hard-scattering observables beyond the next-to-leading logarithmic accuracy. We present two proposals of a soft-gluon effective coupling that extend the CMW coupling to all perturbative orders. Although both effective couplings are well-defined in the physical four-dimensional space time, we examine their behaviour in 𝑑=4−2\ep space time dimensions. We uncover an all-order perturbative relation with the cusp anomalous dimension: the (four dimensional) cusp anomalous dimension is equal to the 𝑑-dimensional soft-gluon effective coupling at the conformal point \ep=𝛽(\as). We present the explicit expressions of the two soft-gluon couplings up to O(\as^2).
In the four-dimensional case we compute the two soft couplings up to O(\as^3).Speaker: Daniel Enrique De Florian Sabaris (International Center for Advanced Studies (AR)) -
83
Revealing proton structure with neural networks
Understanding the internal structure of the proton — that is, how it is built from its fundamental constituents, quarks and gluons — is one of the great challenges of modern high-energy physics. The three-dimensional distribution of quarks and gluons is encoded in terms of the so called generalized parton distributions (GPDs), and the most promising access to these functions is via the process of deeply virtual Compton scattering (DVCS).
We will show our global analyses of the available DVCS data leading to the extraction of relevant structure functions in a model-dependent way. To overcome the problem of model bias, which is particularly dangerous in this context, we describe the analogous procedure using unbiased neural networks. As an application, we discus the possibility of measurement of pressure inside the proton [1].
[1] K. Kumericki, Measurability of pressure inside the proton, Nature 570 (2019) E1
Speaker: Kresimir Kumericki (University of Zagreb) -
84
Dedicated data analyses for improving PDFs: Study of proton parton distribution functions at high x and charm production in charged DIS at HERA
Proton parton distribution functions (PDFs) are poorly constrained by existing data for Bjorken x larger than 0.6, and the PDFs extracted from global fits differ considerably from each other. A technique for comparing predictions based on different PDF sets to observed event numbers is presented. It is applied to compare predictions from the most commonly used PDFs to published ZEUS data at high Bjorken $x$. A wide variation is found in the ability of the PDFs to predict the observed results. A scheme for including the ZEUS high-$x$ data in future PDF extractions is discussed.
Charm production in charged current deep inelastic scattering has been measured for the first time in 𝑒±𝑝 collisions, using data collected with the ZEUS detector at HERA, corresponding to an integrated luminosity of 358 pb−1 separately for 𝑒+𝑝 and 𝑒−𝑝 scattering at a centre-of-mass energy of 𝑠√=318 GeV within a kinematic phase-space region of 200 GeV2<𝑄2< 60000 GeV2 and 𝑦< 0.9, where 𝑄2 is the squared four-momentum transfer and 𝑦 is the inelasticity. The measured cross sections of electroweak charm production are consistent with expectations from the Standard Model within the large statistical uncertainties.
Speaker: Ritu Aggarwal (SPPU) -
85
Investigation of high energy behaviour of HERA data
We analyse the high precision HERA $F_2$ data in the low-$x$, $x<0,01$, and very-low-$x$, $x<0.001$, regions using $\lambda$-fits. $\lambda$ is a measure of the rate of rise of $F_2$ defined by $F_2 \propto (1/x)^{\lambda}$. We show that $\lambda$ determined in these two regions, at various $Q^2$ values, is systematically smaller in the very-low-$x$ region as compared to the low-$x$ region. We discuss some possible physical interpretations of this effect.
Our observation that the value of the exponent $\lambda$ decreases at small values of $x$, indicates that measurements at the future ep colliders, like VHEeP or LHeC will become exciting, as they will approach the high energy limit of the virtual photon-hadron cross sections, where DGLAP and BFKL meets and the confinement effects should become simple.
The analysis is based on Phys.Lett. B802 (2020) 135199.
Speaker: Dr Agnieszka Łuszczak (Cracow University of Technolog & DESY Hamburg) -
86
TMD densities at leading and higher order from the Parton Branching method
We present a new determination of Transverse Momentum Dependent (TMD) parton distributions obtained with the Parton Branching (PB) method at LO, NLO and NNLO. The PB TMDs are extracted from fits to precision DIS data using DGLAP splitting functions at leading and higher order. We extract both the collinear part and the transverse momentum dependent part of the parton densities.
In addition the fit sensitivity to dynamical resolution scales on TMD evolution in different kinematical region of $x$ and $Q^2$ will be investigated.Speaker: Sara Taheri Monfared (Deutsches Elektronen-Synchrotron (DE)) -
87
Determination of the Parton Density Functions of the Proton with the ATLAS data
In this talk we present fits to determine parton distribution functions (PDFs) using inclusive W/Z-boson and W+jets measurements from the ATLAS experiment at the LHC. The ATLAS measurements are used in combination with deep-inelastic scattering data from HERA. The ATLAS W and Z boson data exhibit sensitivity to the valence quark distributions and the light quark sea composition. The parton distribution functions extracted using W+jets data show an improved determination of the high-x sea-quark densities, while confirming the unsuppressed strange-quark density at lower x<0.02 found by previous ATLAS analyses.
Speaker: Mark Sutton -
88
Isolated photon production and pion-photon correlations in high-energy pp and pA collisions
A phenomenological study of the isolated photon production in high energy pp and pA collisions at RHIC and LHC energies is performed. Using the color dipole approach we investigate the productioncross section differential in the transverse momentum of the photon considering three different phenomenological models for the universal dipole cross section. We also present the predictions for the rapidity dependence of the ratio of pA/pp cross sections. As a further test of the formalism, for different energies and photon rapidites we analyse the correlation function in azimuthal angle ∆φ between the photon and a forward pion. The characteristic double-peak structure of the correlation function around ∆φ = π observed previously for Drell-Yan pair production is found for isolated photon emitted into the forward rapidity region which can be tested by future experiments.
Speaker: Dr Michal Sumbera (Nuclear Physics Institute, Acad. of Sciences of the Czech Rep. (CZ))
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71
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Heavy Ions: Session I - PremiereConveners: Dr Barbara Antonina Trzeciak (Czech Technical University in Prague), Dennis Perepelitsa (University of Colorado Boulder)
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89
Measurement of electroweak-boson production in p-Pb and Pb-Pb collisions with ALICE at the LHC
W and Z bosons are clean probes of the initial-state effects in hadronic collisions, being formed in the hard scatterings taking place in the initial stages, and being insensitive to the presence of any strongly-interacting medium. This is especially true at the LHC energies, where having a clear picture of the initial state is mandatory to properly interpret the later stages characterising the complex evolution of p-Pb and Pb-Pb collisions. In particular, measurement of W and Z boson production in p-Pb and Pb-Pb collisions at the LHC provides constraints on the nPDFs of the (anti-)quarks in a phase-space region that is poorly constrained by previous experiments.
ALICE measures W and Z boson production in the muonic decay channels at forward rapidities ($2.5 < y_\mathrm{lab} < ~4$). In this contribution, recent measurements on the Z and W boson production in p-Pb and Pb-Pb collisions at the center-of-mass energies per nucleon pair of $\sqrt{s_\mathrm{NN}} = 8.16$ and 5.02 TeV, respectively, are presented. Results, including invariant production yield and nuclear modification factors as a function of rapidity and collision centrality, are compared to calculations obtained with or without including nuclear modifications of the PDFs, as well as to results obtained by other LHC experiments.
Speaker: Mingrui Zhao (China Institute of Atomic Energy (CN)) -
90
Quarkonia photo-production and Z production in heavy ion collisions
Vector meson photo-production in ultra-peripheral Pb-Pb collisions is sensitive to nuclear parton distribution functions, and probe models of vector meson production in nuclear interactions with strong electromagnetic fields. In pPb collisions, measurements of the Z production in the forward (pPb) and backward (Pbp) configurations are sensitive to the nPDFs in different kinematic domains, such that both probes enable complementary studies of the structure of the nucleus. In this talk, we present the latest results on charmonium production in PbPb ultra-peripheral collisions and on Z production in pPb and Pbp collisions at LHCb.
Speaker: Giulia Manca (Universita` degli studi di Cagliari and INFN, Cagliari, IT) -
91
Electroweak probes in heavy-ion collisions with ATLAS
Electroweak bosons produced in lead-lead (Pb+Pb) collisions are an excellent tool to constrain initial-state effects which affect the rates of hard-scattering processes in nucleus-nucleus interactions. The production yields of massive electroweak bosons, observed via their leptonic decay channels, offer a high-precision test of the binary collision scaling expected in Pb+Pb and a way to quantify nuclear modifications of the parton distribution functions (PDFs). The large samples of Pb+Pb data at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV collected by the ATLAS experiment in 2015, and the corresponding high-statistics $pp$ data at the same collision energy used as a baseline, allow for a detailed experimental study of these phenomena and comparisons to predictions from a variety of theoretical calculations. This talk presents the latest ATLAS results on electroweak boson production, including updated results on Z production and high-precision W boson results in Pb+Pb collisions. Inclusive production of prompt photons in proton-lead~($p$+Pb) collisions at $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV is also covered. Various predictions of nuclear modifications to PDFs are discussed.
Speaker: Jakub Andrzej Kremer -
92
Considerations on the suppression of charged particle production in high energy heavy ion collisions
Results from RHIC for Au-Au and from LHC for Pb-Pb collisions are compiled in terms of $R_{AA}$, $R_{CP}$ and ratio of the $p_T$ spectra, normalized with the corresponding $dN_{ch}/d\eta$, for each centrality to the most peripheral one ($R^N_{CP}$). The studies are focused on the $p_T$ range in the region of maximum suppression evidenced in the experiment. The $R_{CP}$ for 4 GeV/c < $p_T$ < 6 GeV/c as a function of $\sqrt{s_{NN}}$ evidences a suppression enhancement from $\sqrt{s_{NN}}$ = 39 GeV up to 200 GeV after which a saturation sets in up to the highest energy of $\sqrt{s_{NN}}$ =5.02 TeV. For collision energies from 200 GeV (Au-Au) up to 5.02 TeV (Pb-Pb), within the error bars, a good scaling of $R_{AA}$ as a function of <$N_{part}$> is evidenced. This scaling improves for $R_{AA}$, when only the core contribution is considered. $R^N_{CP}$ evidences the same saturation starting from 200 GeV collision energy and a very good scaling as a function of <$N_{part}$> for $\sqrt{s_{NN}}$ =200 GeV (Au-Au) and for $\sqrt{s_{NN}}$ =2.76 TeV and $\sqrt{s_{NN}}$ =5.02 TeV (Pb-Pb). A comparison in terms of Bjorken energy density times formation time ($\varepsilon_{Bj}\cdot\tau$) and particle density per unit of rapidity and overlapping area ($(dN/dy)/S_{\perp}$) is presented.
Speaker: Mihai Petrovici (Horia Hulubei National Institute of Physics and Nuclear Enginee) -
93
Jets and medium evolution in Pb-Pb collisions at the LHC energies from the EPOS initial state
We present the results for PbPb collisions at 2.76 TeV LHC energy from a parton shower integrated with a hydrodynamic evolution. The initial hard (jet) partons are produced along with soft partons in the initial state EPOS approach. The EPOS initial state typically contains multiple hard scatterings in each event. The soft partons melt into a thermalized medium, which is described with a 3 dimensional event-by-event viscous hydrodynamic approach. The jet partons then propagate in the hydrodynamically expanding medium. The total jet energy gets progressively “degraded” according to a state-of-the-art microscopic radiative energy loss Monte Carlo for the low-virtuality jet partons. The full evolution proceeds in a concurrent mode, without separating hydrodynamic and jet parts. We discuss two features of PbPb collision:
1) A jet overlap effect [1] which emerges due to multiple hard parton production in each heavy-ion collision event
2) Jet energy loss in the medium and its modification due to the LPM effect.[1] Iu. Karpenko, J. Aichelin, P. Gossiaux, M. Rohrmoser, and K. Werner,
Phys. Rev. C 101, 014905 (2020)Speaker: Dr Iurii Karpenko (CTU Prague) -
94
Jet production and fragmentation at colliders
Fragmentation (or in general, hadronization) is the transition from a colored and energetic parton to a colorless hadron is a rich and dynamical process in QCD quantified by the fragmentation function. Fast moving hadrons (or jets) are produced by the fragmentation of colored quarks or gluons that are produced during hard collisions at short distances. The determination of a characteristic time scale for the color neutralization would shed light on the properties of color confinement and help answer the question: how hadrons emerge out of quarks and gluons?
Since the earliest days of collider physics, jets have been an important tool in the exploration of QCD and have provided important discoveries and insights, in all colliding systems, including e-e, e-p hadron-hadron, and nucleus-nucleus. With the advances in experimental techniques, and corresponding theoretical progress over time, jets have become precision tools for studying the partonic structure of matter.
Starting at the Relativistic Heavy Ion Collider (RHIC) at BNL, a suppression by a factor of five of the yield of high $p_\mathrm{T}$ hadrons in Au-Au collisions, compared to proton-proton collision at the same energy was observed and called “jet quenching”. The same phenomenon was confirmed by the heavy-ion program at the CERN’s Large Hadron Collider (LHC) where the jet quenching phenomenon was observed at much greater collision energies that became accessible, allowing new and more detailed characterization of the quark-gluon plasma. While interacting with the medium, a modification of the jet structure and a redistribution of jet energy as well as a modification of their fragmentation pattern is expected.
Jets in (SI)DIS are also guaranteed to contribute at the Electron-Ion Collider (EIC) to a variety of key electron-nucleus and electron-hadron physics topics in particular the study of hadronization, aiming to shed light on the nature of color neutralization and confinement.A selection of results (not focussed on a particular experiment) on jet physics will be discussed and compared to theoretical calculations. The measurements that will be discussed may include $p_\mathrm{T}$-differential jet production cross sections or detailed studies of the parton shower through observables like the jet mass, jet fragmentation functions or jet substructure observables. Well defined jet shapes observables can also provide complementary information on the fragmentation process.
Speaker: Alexandre Shabetai (Centre National de la Recherche Scientifique (FR)) -
5:54 PM
Coffee break
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95
Jet Measurements in Heavy Ion Collisions with the ATLAS Experiment
Jets are an important tool to study the hot, dense matter produced in Pb+Pb collisions at the LHC. They are produced at the early stages of the collisions and are expected to be modified as they propagate through the hot and dense medium. This leads to energy loss as well as modification of the jet structure. This talk presents the latest jet measurements from Run 2 heavy-ion collisions data from ATLAS. The results shown in this talk include measurements of the angular distribution of charged particles around the jet axis, measurements of the flavor-dependence of energy loss via b-jets and jets associated with photons and Z bosons, and measurements of the jet internal structure characterized by the transverse momentum scale for the hardest splitting. Furthermore, the latest results on the dijet momentum balance in $pp$, Xe+Xe, and Pb+Pb collisions will be presented. The talk will also show a measurement of the single jet yields as a function of the azimuthal angle with respect to the event plane in Pb+Pb collisions. The data are compared to state of the art theoretical models and provide important information to understand the strength and mechanism of the jet quenching.
Speaker: Helena Santos (LIP - Lisbon) -
96
Universal features of the medium-induced gluon cascade and jet quenching in expanding media
We present a study of the impact of the expansion of deconfined medium on single-gluon emission spectra and the jet suppression factor ($𝑄_{𝐴𝐴}$) within the BDMPS-Z formalism. These quantities are calculated for three types of media (static medium, exponentially decaying medium and Bjorken expanding medium). The distribution of medium-induced gluons and the jet $𝑄_{𝐴𝐴}$ are calculated using the evaluation of in-medium evolution with splitting kernels derived from the gluon emission spectra. A universal behavior of splitting kernels is derived for low-𝑥 and high-𝑥 regimes in the asymptote of large times and its impact on the resulting jet $𝑄_{𝐴𝐴}$ is discussed. For the full phase-space of the radiation, the scaling of jet $𝑄_{𝐴𝐴}$ with an effective quenching parameter is derived. The importance of the medium expansion for precise modeling of jet quenching phenomena as well as steps towards generalizing the results to other jet quenching observables are discussed.
Speaker: Dr Souvik Priyam Adhya (Institute of Particle and Nuclear Physics Faculty of Mathematics and Physics, Charles University) -
97
Overview of the latest jet physics results from ALICE
Collisions of ultra-relativistic heavy ions are used to create strongly interacting matter in the regime of high-energy densities and temperatures. Under these conditions color confinement of quarks and gluons in hadrons breaks down and a new state of matter called Quark-Gluon Plasma is formed. Properties of this medium can be inferred based on observed modifications of produced jets. Recently, new tools were developed to study jet properties more differentially. These observables are based on jet-shape and jet-substructure measurements or employ hadron-jet correlations. The talk will review the latest results from these jet analyses performed by the ALICE Collaboration in pp and Pb-Pb collisions.
Speaker: James Mulligan (University of California, Berkeley (US)) -
98
Jet quenching and effects of non-Gaussian transverse-momentum broadening on di-jet observables
I am going to report on recent study, at a qualitative level, production of jet pairs in ultrarelativistic nuclear collisions within a framework combining High Energy Factorisation (HEF) and in-medium propagation of jet particles that takes into account stochastic transverse forces as well as medium-induced radiation. We find that the resulting di-jet observables feature the behaviour deviating from that of jet-pairs which undergo transverse-momentum broadening following the Gaussian distribution. The result follows from application of only recently solved by Kutak, Straka, Placzek evolution equation formulated by Blaizot, Dominguez, Iancu, Mehtar-Tani, Dominguez.
The application of recently solved equation allows for studies of interplay of energy loss via branchings and rescattering leading to broadening therefore in the end to more detailed study of structure of jets in Heavy Ion Collisions.Speaker: Krzysztof Kutak (Instytut Fizyki Jadrowej Polskiej Akademii Nauk) -
99
Hard probes in heavy ion collisions with CMS
We review recent CMS results on hard probes of heavy ion collisions, including jet and electroweak boson production.
Speaker: Xiao Wang (Univ. of Illinois at Chicago) -
100
Precision Jet/Event Substructure Using Collinear Drop
I will present a new class of jet/event substructure observable called collinear drop and its use in the search for novel signatures of jet modifications and medium responses. It is demonstrated using Monte Carlo simulations generated with Jewel how underlying jet-medium interactions can be systematically examined using collinear-drop observables. Studies using LEP open data and applications to Electron Ion Collider will be discussed. Analytic insights on the modifications of such observables will also be given using soft-collinear effective theory with Glauber gluon interactions.
Speaker: Dr Yang-Ting Chien (Stony Brook University)
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89
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Astro-particle Physics and Cosmology: Session I - PremiereConvener: Constantinos Skordis (Institute of Physics AS CR)
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101
Dark matter Annihilation in Most Luminous and the Most Massive Ultracompact Dwarf Galaxies (UCD)
We explore the potential astrophysical signatures of dark matter
(DM) annihilations in ultracompact dwarf galaxies (UCDs) considering two of the richest known galaxy clusters within 100 million light-years, nominally, Virgo and Fornax. Fornax UCD3 is the most luminous UCD and M59 UCD3 is the most massive UCD. With the detection of a 3.5 million solar mass black hole (BH) in Fornax UCD3, we carefully model several DM enhanced profiles scenarios, considering both the presence of the supermassive black hole (SMBH) and DM. For Fornax UCD3, the comparison of the stellar and dynamical masses suggests that there is little content of DM in UCDs. M59 UCD3 did not receive the same attention in simulations as Fornax UCD3, but deep radio imaging and X-ray observations were performed for M59 UCD3 and can be used to place limits in DM content of these UCDs. We work with an average estimative of dark matter content considering the Salpeter and Kroupa mass functions. We model Fornax UCD3 and M59 UCD3 to have a DM content that is the average of these mass functions. We then analyze the constraints for Fornax and M59 UCD3 coming from gamma-ray and radio sources considering in our simulations, a dark matter particle with mass between 10 − 34 GeV. In the absence of strong γ-ray signatures, we show that synchrotron emission from electrons and positrons produced by DM annihilations can be very sensitive to indirect DM search. We find that DM parameters can be significantly constrained at radio frequencies and the spike profiles play an interesting rule in order to deep study the enhancements of DM & BH interactions in ultracompact galaxies.Speaker: Prof. Fortes Elaine (Unipampa) -
102
Heat Engine for Black Holes in Presence of Cyclic Thermodynamics Behavior
The study of astrophysics context of massive theory leads to the black hole heat engine may be regarded as a possible energy source of the high energy astrophysical phenomena. Therefore, a black hole engine may be regarded as a possible source of power gamma rays and ultrahigh energy cosmic rays. Propose of this research was study to heat engine provided by black holes in presence of cyclic thermodynamics behavior. The main motivation was to investigate the rate of change of the cyclic process based on massive theory leads to the effect as different of the efficiency of black hole engines in massive gravity. It would be interesting to investigate the efficiency calculated on the horizon with these three different topologies were spherical flat and hyperbolic which then make a comparison. The results in this research will be shown that the highest efficiency for the heat engine belongs to black holes with the hyperbolic horizon, while the lowest one belongs to the spherical black holes.
Speaker: Dr Atirat Maksuwan (Pathumwan Institute of Technology) -
103
Production of Thermal Axions across the ElectroWeak Phase Transition
If there are light axions in nature they will very probably leave a cosmic background, just like neutrinos. In this work we complete the study of thermal axion production above the QCD Phase Transition (QCDPT) by including the scatterings of the axion with the longitudinal components of the W and Z bosons. We study the predictions for pa4ticular QCD axion scenarios, like the KSVZ and the so-called Minimal Flavour Violating Axion.
Speaker: Fernando Arias Aragón (Universidad Autónoma de Madrid) -
4:45 PM
Coffee break
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104
Generation of magnetic fields in cosmic string wakes
We describe a novel method of generating magnetic fields in cosmic string wakes from neutrino currents. We show that neutrino currents act as a cross-perturbation across the cosmic string wake. This cross perturbation along with the high Reynolds number generates a magnetic field in the wake of the cosmic string. The neutrino current is generated by the neutrinos rotating around the Abelian Higgs strings. As the string moves through the cosmic plasma, the velocity kick generated by the motion of the string will enhance the neutrino current in the wake region. The neutrino current density depends on its distance from the string and is oscillatory in nature. This leads to neutrino density gradients in the plasma. We have shown that these neutrino gradients give rise to electron gradients in the plasma, which in turn generate magnetic fields of the order of $10^{13}$ Gauss.
Speaker: Sovan Sau (University of Hyderabad) -
105
On the Abraham-Minkowski controversy: Can the time delay of the gamma-ray bursts travelling through interstellar space be explained without invoking the Lorentz-invariance violation?
The ANTARES neutrino telescope and other experiments are searching for more detailed information on the previously observed shifted high-energy neutrinos from the gamma-ray bursts travelling through interstellar space. Many theoretical models have been proposed to explain this phenomenon, based on assuming the Lorentz-invariance violation. In this talk I shall show that the dispersion phenomenon of gamma-ray in an interstellar space considered as a cosmic plasma can explain this effect. This in turn indicates that invoking the drastic assumption of Lorentz-invariance violation for such a problem can be premature.
Speaker: Prof. Masud Chaichian (University of Helsinki) -
106
New Properties of primary and secondary cosmic rays measured by AMS
We present precision high statistics measurements of primary cosmic rays protons, Helium, Carbon and Oxygen and the secondary cosmic rays Lithium, Beryllium and Boron measured by Alpha Magnetic Spectrometer on ISS in the rigidity range from 2 GV to 3 TV.
These measurements are based on more than one billion nuclei collected by AMS during first 7 years of operation from May 2011 to May 2018. The unexpected properties of these cosmic rays as well as high statistics secondary-to-primary flux ratios such as Li/C,Be/C, B/C, Li/O, Be/O and B/O will be discussed.Speaker: Dr Mercedes Paniccia (Universite de Geneve (CH)) -
6:30 PM
Coffee break
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107
New Properties of Neon, Magnesium, Silicon, and Sulfur Primary Cosmic Rays observed by the Alpha Magnetic Spectrometer on the International Space Station
Neon, Magnesium, Silicon, and Sulfur nuclei in cosmic rays are thought to be mainly of primary origin, they are mainly produced and accelerated in astrophysical sources. We report the latest precise measurements of the Ne, Mg, Si, and S individual spectra in the rigidity range from 2 GV to 3 TV by the Alpha Magnetic Spectrometer based on the data collected during its first 7 years of operation. Unexpectedly, compared with the spectra of light nuclei Helium, Carbon, and Oxygen, the spectra of heavy nuclei Ne, Mg, Si, and S show distinctly different new properties.
Speaker: Qi Yan (Massachusetts Inst. of Technology (US)) -
108
Anisotropy of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the ISS
Analysis of anisotropy of the arrival directions of galactic protons, electrons and positrons has been performed with the Alpha Magnetic Spectrometer on the International Space Station. These results allow to differentiate between point-like and diffuse sources of cosmic rays for the explanation of the observed excess of high energy positrons. The AMS results on the dipole anisotropy are presented along with the discussion of implications of these measurements.
Speaker: Miguel Angel Velasco Frutos (Centro de Investigaciones Energéti cas Medioambientales y Tecno) -
109
Precision Measurement of the Monthly Boron, Carbon and Oxygen Fluxes in Cosmic Rays with the Alpha Magnetic Spectrometer on the International Space Station
Cosmic Rays (CR) inside the Heliosphere are subject to the effects of the Solar Modulation, resulting from their interaction with the solar wind and with the interplanetary magnetic field. These effects are strongly related to the solar activity and lead to a temporal variation of the cosmic ray intensity near Earth for rigidities up to few tens of GV. Previous AMS results on proton and helium spectra showed how the two fluxes behave differently in time. To better understand these unexpected results, one should therefore study the next most abundant species such as carbon, oxygen, and boron.
In this contribution, the precision measurements of the monthly boron, carbon and oxygen fluxes for the period from May 2011 to May 2018 with Alpha Magnetic Spectrometer on the International Space Station are presented. This period covers the ascending phase of solar cycle 24 together with the reversal of the Sun’s magnetic field polarity through the maximum. The detailed temporal variations of the boron, carbon and oxygen fluxes are shown up to rigidities of 60 GV. The time dependence of the B/C, B/O and C/O fluxes ratios are also presented.Speaker: Jian Tian (Universita e INFN, Perugia (IT)) -
8:15 PM
Coffee break
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8:25 PM
General discussion
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101
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Dark Matter Detection: Session I - PremiereConveners: Dr Silvia Scorza (SNOLAB), Torben Ferber (DESY)
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110
New Inelastic Channels for Sub-GeV Dark Matter Scattering
As the search for dark matter continues down to lower and lower masses, the kinematics of sub-GeV dark
matter scattering require moving beyond the approximation of free-particle scattering. I will describe two inelastic
channels relevant for sub-GeV dark matter detection which necessarily involve the condensed matter properties of
common detector materials: the Migdal effect in liquid nobles, and plasmon excitation in semiconductors. I will
outline the theoretical basis for these processes, discuss the importance of many-body effects in accurately
predicting the scattering rates, and speculate on whether these processes have already been observed at numerous
experiments.Speaker: Yonatan Kahn (University of Illinois) -
111
Dark Matter - phonon scattering
Light dark matter interacting in a crystal or fluid must scatter off a
collective excitation (phonon) rather than off individual nuclei. I will
set up the appropriate low energy effective theory and show how to
calculate the dark matter scattering rate for various dark matter models
and target materials.Speaker: Simon Knapen (CERN) -
112
String fragmentation in supercool confinement as a new dark matter production mechanism
A new strongly-coupled sector can feature a supercooled confinement transition in the early universe. When fundamental quanta of the strong sector are swept into expanding bubbles of the confined phase, the distance between them is large compared to the confinement scale. The string of flux linking the fundamental quanta fragments and in the process produces an enhanced number of composite states. Furthermore, the resulting composite states are highly boosted in the CMB frame, which leads to additional particle production through the subsequent deep inelastic scattering. This opens several new avenues of investigation, in this talk I will focus on the one related to the composite dark matter relic density.
Speaker: Filippo Sala (LPTHE) -
4:45 PM
Coffee break
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113
Recent Searches for Hidden-Sector Particles with BABAR
Many models of dark matter and hidden sectors predict new particles with masses below the electroweak scale. Low-energy electron-positron colliders such as BABAR are ideally suited to discover these hidden-sector particles. We present several recent BABAR searches for low-mass hidden- sector particles, including new searches for prompt and long-lived leptonically decaying hidden scalars produced in association with tau leptons. This search is sensitive to viable models that could account for the muon $g-2$ excess. We also present results a search for dark muonic forces, and for invisible particles produced in six-quark final states. These examples show the importance of $B$-factories in constraining and discovering new hidden-sector physics beyond the Standard Model.
Speaker: Yunxuan Li (California Institute of Technology) -
114
Search for an Axion-Like Particle in B -> K a, with a -> gamma gamma at BABAR
Many extensions of the Standard Model include the possibility of light new particles, such as axions or dark matter candidates. These scenarios can be probed using the large data sets collected by $B$-factories, complementing measurements performed at the LHC.
We report on a search for an Axion-like particle (ALP), $a$, produced in the Flavor-Changing Neutral-Current decay $B\to K a$, with $a\to \gamma\gamma$, which is expected to be competitive with the corresponding Standard-Model electroweak processes. This search, performed by using a dataset of about 470 million $B\bar{B}$ pairs collected by the $BABAR$ experiment at the PEP-II $e^+e^-$ collider, is sensitive to ALP masses in the range 0 - 4.78 GeV.Speaker: Brian Shuve (Harvey Mudd College) -
115
Dark Sector first results at Belle II
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider
is a substantial upgrade of the B factory facility at the Japanese KEK laboratory.
The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and
the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more
than its predecessor. During 2018, the machine has completed a commissioning run,
recording a data sample of about 0.5 fb$^{-1}$. Main operations started in
March 2019 with the complete Belle II detector: an integrated luminosity
of 10 fb$^{-1}$ has been collected so far. These early data sets,
with specifically designed low multiplicity triggers, offer already the
possibility to search for a large variety of dark sector particles in
the GeV mass range, complementary to LHC and to dedicated low energy experiments.
The talk will review the status of the dark sector searches at Belle II, with a focus
on the discovery potential of the early data, and show the first results.Speaker: Enrico Graziani (Universita' di Roma III) -
6:15 PM
Coffee break
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116
DarkSide-20k and the Direct Dark Matter Search with Liquid Argon
Dual phase noble liquid Time Projection Chambers (TPCs) offer a
competitive and scalable way to search for dark matter directly via
elastically scattering off of detector target nuclei and electrons.
The Global Argon Dark Matter Collaboration (GADMC) is undertaking an
ambitious global program from the extraction and purification of
Underground Argon (UAr), depleted in 39Ar which reduces the internal
background, to the development of $25 cm^2$ Silicon Photo Multiplier
(SiPM) modules capable of resolving single photoelectrons.
DarkSide-20k is the next stage of this program and will be the next
generation dual phase Argon TPC. DarkSide-20k will be housed in the
Gran Sasso underground laboratory (LNGS) and has an exposure goal of
~100 tonne-years with zero instrumental background in expectation of a
WIMP-nucleon cross section of $10^{-47} cm^2$ for a WIMP mass of 1TeV/$c^2$
during a 5-year run. An overview of the DarkSide experimental program
will be presented with a focus on the upcoming DarkSide-20k detector
and the new technologies involved.Speaker: Dr Luigi Pio Rignanese (Universita e INFN, Bologna (IT)) -
117
The Light Dark Matter eXperiment, LDMX
The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus on a narrower range of masses: the natural scenario where dark matter originates from thermal contact with familiar matter in the early Universe requires the DM mass to lie within about an MeV to 100 TeV. Considerable experimental attention has been given to exploring Weakly Interacting Massive Particles in the upper end of this range (few GeV – ~TeV), while the region ~MeV to ~GeV is largely unexplored. Most of the stable constituents of known matter have masses in this lower range, tantalizing hints for physics beyond the Standard Model have been found here, and a thermal origin for dark matter works in a simple and predictive manner in this mass range as well. It is therefore a priority to explore. If there is an interaction between light DM and ordinary matter, as there must be in the case of a thermal origin, then there necessarily is a production mechanism in accelerator-based experiments. The most sensitive way, (if the interaction is not electron-phobic) to search for this production is to use a primary electron beam to produce DM in fixed-target collisions. The Light Dark Matter eXperiment (LDMX) is a planned electron-beam fixed-target missing-momentum experiment that has unique sensitivity to light DM in the sub-GeV range. This contribution will give an overview of the theoretical motivation, the main experimental challenges and how they are addressed, as well as projected sensitivities in comparison to other experiments.
Speaker: Andrew James Whitbeck (Texas Tech University (US)) -
118
Dark Matter searches with the ATLAS detector
The presence of a non-baryonic dark matter (DM) component in the Universe is inferred from the observation of its gravitational interaction. If dark matter interacts weakly with the Standard Model it would be produced at the LHC, escaping the detector and leaving a large missing transverse momentum as their signature. The ATLAS detector has developed a broad programme to directly search for DM. The results of recent searches on 13 TeV pp data, their interplay and interpretation will be presented.
Speaker: Ben Carlson (University of Pittsburgh)
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110
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Operation, Performance and Upgrade of Present Detectors: Session I - PremiereConveners: Sowjanya Gollapinni (Los Alamos National Laboratory (US)), Stefania Beole (Universita e INFN Torino (IT)), Jiri Kroll (Czech Academy of Sciences (CZ))
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119
THE LIGO-VIRGO OBSERVATION RUN 3 (APRIL 2019 – APRIL 2020)
Observation Run 3 (O3) is the longest period of data taking for the two Advanced LIGO detectors and the Advanced Virgo detector to date. From April 1st, 2019 to April 30th, 2020, the instruments accumulated 12 months of data, with a 1-month commissioning break in October 2019. In this talk, I will review the performance of the three detectors both separately and within the global network of ground-based gravitational-wave interferometric detectors: sensitivity, duty cycle, noise stability and variations. I will briefly describe the O3 public alerts and the first published results of this run. To conclude, I will summarize the plans of the two collaborations for the coming years: alternatively upgrade phases and data taking periods with improved performance.
Speaker: Dr Nicolas Arnaud (LAL (CNRS/IN2P3 and Université Paris-Sud)) -
120
The AugerPrime Upgrade of the Pierre Auger Observatory.
To answer many questions still open in the field of Ultra-High-Energy Cosmic Rays, the Pierre Auger Collaboration started a significant upgrade of the Observatory, called AugerPrime.
The main goal of the upgrade is to improve the mass composition sensitivity of the surface detector on a shower-to-shower basis, in order to explore the cosmic ray composition at energies above 10$^{19}$eV. At energies unexplored by terrestrial accelerators, it will be possible to study the properties of multi-particle production and to search for new or unexpected changes of hadronic interactions. Moreover, in the region of the suppression of the cosmic ray flux, charged particle astronomy will benefit from the knowledge of the fraction of light primaries for composition-selected anisotropy searches.
After a discussion of the motivations for upgrading the Pierre Auger Observatory, a description of the detector upgrade will be provided, together with an evaluation of the expected performance and the improved physics sensitivity. Finally the first data collected will be presented.
Speaker: Gabriella Cataldi (INFN, Sezione di Lecce, Lecce, Italy) -
121
The Mu2e Electromagnetic Calorimeter
The “muon-to-electron conversion” (Mu2e) experiment at Fermilab will search for the Charged Lepton Flavour Violating neutrino-less coherent conversion /mu^-N(A,Z) -> e-N(A,Z) of a negative muon into an electron in the field of an aluminum nucleus. The observation of such physics process would be the unambiguous evidence of the existence of physics beyond the Standard Model. The Mu2e detector is composed of a tracker and an electromagnetic calorimeter and an external veto for cosmic rays. The calorimeter plays an important role in providing excellent particle identification capabilities, a fast online trigger filter and aiding track reconstruction. The calorimeter requirements are to provide a large acceptance for ~100 MeV electrons and reach: 1) a time resolution better than 0.5 ns; 2) an energy resolution O(10%); 3) a position resolution of 1 cm. The detector has been designed as a state-of-the-art crystal calorimeter and employs pure Cesium Iodide (CsI) crystals and UV-extended Silicon PhotoMultipliers (SiPMs) readout by fast analog electronics with a digitization at 200 Msps. A design consisting of two disks, each one made of 674 crystals readout by two large area 2x3 arrays of SiPMs of 6x6 mm^2 area can largely satisfy Mu2e requirements. The detector has to satisfy many other demanding requests, such as keeping the required performance in an extremely hostile environment with 1 tesla axial magnetic field, high radiation level and 10^-4 Torr vacuum. We have verified with a campaign of test beams that the CsI crystals will withstand the expected dose and fluence with a small light yield loss and the SiPMs will function under the expected neutron irradiation when cooled to 0 C. This requires a good engineering design of the calorimeter mechanics and its cooling system, in terms of performance as well as reliability.
A large scale detector prototype has been constructed and tested at the beam test facility in Frascati. It consists of 51 pre-production crystals readout by a 102 SiPMs. All the tests and progresses done so far to define the calorimeter design, the satisfying results obtained with the test beam of the prototypes as well as the current production phase will be reported in this presentation. At the moment, all the components for the first disk have been tested and characterized. According to the Mu2e Collaboration plans, calorimeter construction will begin in spring 2020.Speaker: Luca Morescalchi (INFN - Pisa) -
122
Construction and performance of 4-D CsI calorimeter for the $K_L¥to ¥pi^0¥nu¥bar{¥nu}$ search of KOTO experiment
One of the key issues of the search for the $K_L\to \pi^0\nu\bar{\nu}$ decay mode is to suppress the backgrounds to the signature with only two photons from the $\pi^0$ in the final state. We use an electromagnetic calorimeter and hermetic veto counters in the KOTO experiment at J-PARC. The calorimeter is made of 50 cm-long undoped CsI crystals stacked in a 1.9 m-diameter cylinder. Each crystal is read out with a PMT on the back surface of the crystals. A major background is caused by neutrons generating two showers in the calorimeter. Neutrons tend to have interactions deeper than photons. In the autumn of 2018 we upgraded the calorimeter by installing 4000 silicon photomultipliers (SiPMs) on the front surface of the crystals. The depth information is available by measuring the timing difference between SiPMs and PMTs. The construction and performance of this new calorimeter by using data of 2019 will be presented. Less than 0.5 neutron background events are expected when we reach the sensitivity of one $K_L\to \pi^0\nu\bar{\nu}$ event. The signature has a branching fraction of $(3.0\pm0.3)\times10^{-11}$ in the standard model.
Speaker: Katsushige Kotera (DESY/Shinshu University (JP)) -
123
Analysis of the magnetic field in the Fermilab muon g-2 experiment
The muon g-2 experiment at Fermilab seeks to confirm or deny the ~3.5 $\sigma$ discrepancy between the Standard Model prediction of the muon anomalous magnetic moment, $a_{\mu}$, and its experimental value. The experiment measures $a_\mu$ directly from the ratio of the muon precession frequency in a uniform storage ring magnetic field to the Larmor frequency of free protons in the same field. Every few days, an NMR ‘trolley’ maps out the storage ring field. Field drifts between trolley runs are tracked by ‘fixed’ NMR probes embedded in the vacuum chamber walls. These measurements are interpolated to determine the field in the storage region, which is convolved with the muon beam distribution to determine the effective magnetic field, $\langle$B$\rangle$. A precise determination of $\langle$B$\rangle$ is crucial; half of the error budget is attributed to the magnetic field uncertainty. The magnetic field analysis techniques and a summary of the results will be presented.
Speaker: Saskia Charity (Fermi National Accelerator Laboratory) -
124
Muon g-2 beam and spin systematic effects for Run-1
The muon g-2 Experiment at Fermilab measures the anomalous magnetic moment, $a_\mu$, with improved precision compared to the previous experiment at Brookhaven National Lab.
The greater than 3 standard deviations difference between Standard Model prediction and the previous BNL, $a_\mu$, measurement hints at the possibility of new physics. Positive polarized muons are circulated in the storage ring and the experiment precisely determines the muon anomalous precision frequency, $\omega_a$, (spin precession relative to momentum). The $\omega_a$ is determined from calorimeter measurements of decay positron time and energy. The experiment also needs to precisely determine the average magnetic field seen by the muons, which is based on continuous NMR probe measurements. A detailed understanding of beam and spin systematic effects is required for the precise determination of $\omega_a$. This talk gives a review of the beam and spin systematic effects that are significant for determination of $\omega_a$ in the 2018 Run-1 analysis.Speaker: Dr Sudeshna Ganguly (University of Illinois at Urbana-Champaign) -
125
ALPIDE pixel detector for tracking in space.
The ALPIDE MAPS chip used in the ALICE silicon tracker upgrade, represents the state of the art for pixel-based tracking with silicon.
We investigated the possibility to use the ALPIDE chip in space applications using a setup derived from the ALICE Outer Barrel HIC.
We first addressed the issue of the power consumption and we will report on a special setup that provides a relevant power saving.
We then passed to address heat dissipation, material qualification for space, performance in vacuum and resistance to launch vibrations.
From our qualification test the ALPIDE chip results as a viable solution for space applications.Speaker: Paolo Zuccon (Universita degli Studi di Trento and TIFPA Trento) -
5:15 PM
Coffee break
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126
The MicroBooNE Experiment
MicroBooNE is a 100-ton scale liquid-argon time projection chamber (LArTPC) neutrino experiment located on the Booster neutrino beamline at Fermilab. The experiment first started collecting neutrino data in October 2015. The detector, the first in the short-baseline neutrino program at Fermilab, is the longest operating LArTPC to date and plays an important role in a phased program towards the construction of massive kiloton scale detectors for future long-baseline neutrino physics (DUNE). We present results on the operation and performance of the detector after four years of data taking, highlighting accomplishments towards reconstruction, calibration and detector physics.
Speaker: Ralitsa Sharankova (Tufts University) -
127
Construction, installation and operation of ProtoDUNE-SP
The single-phase liquid argon TPC at CERN (ProtoDUNE-SP) is an engineering prototype for the first module of the DUNE far detector. This prototype which has dimensions of a cube of about 10m edge, provide full validation of the use of the membrane tank technology for large dimension cryostats. Furthermore, the very high performance of the protoDUNE-SP TPC with more than 500 days of continuous and stable operation, demonstrated the reliability of the LAr detection technology at a scale never tested before. In this talk we will review the main characteristics and milestones of the construction and installation of protoDUNE-SP which provide a series of benchmarks for DUNE. The performance for several different detector working points will also be discussed.
Speaker: Stefania Bordoni (Michigan State University (US)) -
128
Performance of photon detectors in ProtoDUNE-SP
The single-phase liquid argon prototype at CERN (ProtoDUNE-SP) is designed to act as a testbed and prototype for the elements of the first far detector module of DUNE. ProtoDUNE-SP collected data in the H4-VLE beamline at CERN in the autumn of 2018 and accumulated 4M particles (electrons, muons, pion, kaons and protons) ranging from 0.3 to 7 GeV/c and a large number of cosmic ray events since then. ProtoDUNE-SP employs three different photon detector technologies. This talk will present the performance of the photon detectors in ProtoDUNE-SP, including detector calibration, efficiency measurements, attenuation studies, timing resolution, calorimetric energy reconstruction from scintillation light and energy resolution of electrons.
Speaker: Dante Totani (Fermi National Accelerator Lab. (US)) -
129
Measurement of space charge effects in ProtoDUNE-SP
The accumulation of positive ions in a LArTPC located on the surface can distort the electric field and the reconstructed particle trajectories. It is critical to understand and correct for the space charge effects in order to achieve the desired spatial and calorimetric resolutions in the LArTPC. This talks will present the measurement of space charge effects using cosmic ray muons in ProtoDUNE-SP.
Speaker: Michael Mooney (Colorado State University) -
130
Energy calibration of the ProtoDUNE-SP TPC
The single-phase liquid argon prototype at CERN (ProtoDUNE-SP) acts as a validation of the design for the DUNE single-phase far detector. With a total mass of 770 tons, it is the largest monolithic liquid argon single-phase time projection chamber in the world. ProtoDUNE-SP collected test-beam in autumn of 2018 and has been collecting cosmic and special calibration data since the end of 2018. With more than 500 days of continuous operation, the long-term performance, stability and calorimetric measurements of the detector will be discussed in this talk.
Speaker: Richard Diurba (University of Minnesota) -
131
The MCP based Large Area PMTs for Neutrino Detector
The large scalar neutrino detectors (JUNO, HyperK), need the 20 inch area PMTs as the photo-detection device for their large photocathode coverage and less electronic channels. In 2009, the researchers at IHEP have conceived a new concept of large area PMTs, of which the small MCP units replace the bulky Dynode chain. After several years R&D, the 20 inch MCP-PMT was successfully produced. This type of PMT has large sensitive area, high QE, and large P/V for good single photon detection. The JUNO ordered 15000 pic 20 inch MCP-PMTs in Dec.2015. Then, from 2017 to 2020, all the 20-inch PMTs will be produced and tested one by one in the company for JUNO. This presentation will talk about the R&D, the mass production and batch test result of the 13K pieces of MCP-PMT prototypes for JUNO. Further more, another Flower-liked MCP-PMT was designed with the TTS less than 5ns, and this new type of 20 inch MCP-PMT has already evaluated by the PMT group in HyperK, and also be used in the LHAASO project in China.
Speaker: Sen Qian (Institute of High Energy Physics,CAS) -
132
Performance of the SoLid reactor neutrino detector
The SoLid collaboration operates since 2018 a 1.6 ton neutrino detector near the Belgian BR2 reactor, with as a main goal the search for observation of the oscillation of electron anti-neutrinos to previously undetected flavor states.
The highly segmented SoLid detector employs a novel compound scintillation technology based on PVT scintillator in combination with a LiFZnS screens containing 6Li isotopes. The experiment has demonstrated a channel-to-channel response that can be controlled to the level of a few percent, an energy resolution of better than 14% at 1 MeV, and a determination of the interaction vertex with a precision of 5cm.In this contribution we will discuss the technology choices that were made to construct the SoLid experiment, the experience gained from its commissioning, calibration, and the detector performance characteristics during two years of non-stop operation. We will also discuss an ongoing upgrade program of the detector and the expected improvements in performance associated with that.
Speaker: Noe Roy (Laboratoire de Physique des 2 infinis Irène Joliot-Curie) -
7:00 PM
Coffee break
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133
The sPHENIX experiment at RHIC
The sPHENIX experiment is the successor the PHENIX experiment at RHIC and is optimized to study heavy flavor and jets arising from heavy ion collisions. The detector utilizes advanced technologies such as a monolithic active pixel vertex detector while also repurposing technologies originally from other high energy experiments such as BaBar, ATLAS and ALICE. In this talk we will show the design and status of the sPHENIX detector whilst also presenting the projected physics capabilities and planned measurements that the collaboration will work to achieve. sPHENIX is expected to begin data taking in 2023.
Speaker: Cameron Dean (Los Alamos National Laboratory (US)) -
134
ALICE upgrades for Run 3
The ALICE detector at the LHC is undergoing major upgrades during the Long Shutdown 2 (2019/20). A new Inner Tracking System (ITS) is being installed and the Time Projection Chamber (TPC) has been equipped with new GEM-based read-out chambers. Together with the new front-end-electronics they will enable us to read out the TPC continuously and record the full minimum-bias interaction rate of 50 kHz in Pb-Pb. The new Monolithic Active Pixel Sensors used for the ITS will significantly improve the impact parameter resolution and tracking efficiency, especially for particles with low transverse momentum, as well as the readout rate capability. In addition, a pixel tracker will be installed in front of the muon spectrometer, and the readout electronics of several other detectors are being replaced with faster technology. These upgrades also require a completely new online computing system that has the dual task of data acquisition and performing the first pass of the reconstruction to compress data and remove noise hits from the data stream. This talk will summarize the motivation and realization of the upgrades and report on the status of the installation and commissioning.
Speaker: Stefano Matthias Panebianco (Université Paris-Saclay (FR)) -
135
Status of the Fast Interaction Trigger for ALICE Upgrade
As part of the preparations for the LHC Run 3 and 4, the ALICE experiment at CERN is making a thorough upgrade of the setup. In particular, all ALICE subsystems have to cope with the increased interaction rate of 50 kHz in Pb-Pb and up to 1 MHz in pp collisions. Comparing with Run 2, this is up to two orders of magnitude more collisions. The solution for the majority of ALICE detectors is to switch to a continuous readout, but several of the older systems (TRD, CPV, HMPID, EMCAL, DCAL and PHOS) would still need an external trigger or a wakeup signal.
The Fast Interaction Trigger (FIT) will generate a minimum-bias and a multiplicity trigger with the maximum latency below 425 ns. It will also measure collision time with a resolution of < 40 ps and serve as the main ALICE luminometer, providing direct, real-time feedback to the LHC for the beam tuning. In the offline analysis FIT will aid in the reconstruction of the vertex position, assess forward particle multiplicity, centrality and event plane, and will be used for the study of diffractive physics at forward rapidity.
FIT consists of three sub-systems: a fast Cherenkov detector array using MCP-PMTs as photosensors, a large scintillator ring employing a novel light collection system, and a scintillator-based Forward Diffractive Detector. After a short description of the detector components, functionalities and a brief summary of the physics objectives, the key test results of the assembled detector will be presented and discussed.
Speaker: Maciej Slupecki (Helsinki Institute of Physics (FI)) -
136
Performance of the LHCb detector in the Run 2
The LHCb experiment is a flavour physics detector, designed to study decays of b and c hadrons for measurements of CP violation and rare decays. Its performance is based on precision tracking and particle-identification systems. In order to accomplish its wide program of physics measurements, the LHCb collaboration has developed in the past years a set of algorithms for reconstruction of the trajectories of charged particles, as well as identification of charged and neutral particles. Several data-driven approaches have been developed to provide a precise calibration of the tracking and particle-identification efficiencies, which are crucial ingredients of many physics analysis. A number of novel strategies have been developed during Run 2 of the LHC to improve the precision of this calibration. This talk presents an overview of the LHCb performance in Run 2 of the LHC, with emphasis on recent improvements.
Speaker: Martina Pili (University of Oxford (GB)) -
137
The LHCb Upgrade Programme for Run 3 and Run 4
The LHCb experiment at the LHC is designed to capture decays of b- and c-hadrons for the study of CP violation and rare decays. It has already had a transformative impact in the field of flavour physics as well as making many general purpose physics measurements in the forward region. At the end of Run-II, many of the LHCb measurements will remain statistically dominated. For this reason the experiment is being upgraded in a first step - Upgrade I - to run at higher luminosity of 2$\times 10^{33}$cm$^{-2}$s$^{-1}$ after 2020. The trigger scheme, which currently has a 1 MHz lowest level hardware rate, will be transformed to a strategy whereby the entire experiment is read out at 40 MHz to a flexible software trigger. The increased luminosity and trigger efficiency anticipated at the upgrade will allow a huge increase in precision, in many cases to the theoretical limit, and the ability to perform studies beyond the reach of the current detector. In addition the flexible trigger and unique acceptance opens up opportunities in topics apart from flavour, reinforcing the role of LHCb as a general purpose detector in the forward region In order to allow the triggerless readout the front end electronics of all subdetectors will be changed, and many subdetectors will be upgraded to cope with the increased occupancy and radiation levels. During the long shutdown between Run 3 and Run 4 the most irradiated parts of the detector will be replaced and other detector consolidation and improvement steps will be carried out.
Speaker: Federico Alessio (CERN) -
138
The LHCb VELO Upgrade
The LHCb experiment is a detector at the LHC designed to capture decays of b- and c-hadrons for the study of CP violation and rare decays. At the end of Run-II, many of the LHCb measurements remain statistically dominated. For this reason the experiment is currently being transformed, in the Upgrade I programme, to run at higher luminosity from Run III onwards. The trigger scheme will be transformed to read out at 40 MHz to a flexible software trigger. In order to allow the new readout scheme the front end electronics will be changed, and the detectors need cope with the increased occupancy and radiation levels anticipated at the upgrade. The Vertex Locator (VELO) surrounding the interaction region, whose role is to reconstruct and trigger on the primary and secondary vertices of the events.
The upgraded VELO is composed of 52 hybrid silcon pixel modules placed along the beam axis, divided into 2 retractable halves. Each module is equipped with 4 silicon pixel tiles, each read out by 3 VeloPix ASICs. The pixels have a square pitch of 55 microns and the sensors are produced in 0.2 mm thick p-in-n type silicon. The sensors must withstand an integrated fluence of um^2, a roughly equivalent dose of 400 MRad The highest occupancy ASICs will have pixel hit rates of 800 Mhit/sf, with a total rate of 1.6 Tbit/s for the whole detector. The VELO upgrade tiles are mounted onto a cooling substrate made of thin silicon plates with embedded micro-channels that allow the flow of liquid CO$_2$. The secondary vacuum in which the modules are located is separated from the beam vacuum by a thin custom made foil. This foil is be manufactured through a novel milling process and possibly thinned further by chemical etching. The upgraded VELO is currently under construction. The detector R\&D, module thermal performance, and the VELO Upgrade production status will be presented.
Speaker: Peter Svihra (University of Manchester (GB)) -
139
The pixel vertex detector at Belle II
The vertex detector at Belle II has four outer layers of silicon strip detectors (SVD) and two inner pixel layers (PXD) at a distance of 14 and 22 mm to the interaction point. The PXD is based on DEPFET technology, which combines signal generation and first amplification in a single device and allows for the construction of a very light-weight device. The material budget of a single layer inside the acceptance region is only about 0.2% of a radiation length including all structures needed for support and thermal management. This is only possible with the unique approach of the “all-silicon module” where all read-out ASICs and interconnects are integrated in a micro-machined piece of silicon with the active DEPFET pixel sensor as its integral part.
The Belle II PXD Collaboration designed and fabricated the sensor, the read-out and steering ASICs, the low-mass module and ladder concept, services and power supplies, cooling, DAQ system and slow control. It is the first time that the DEPFET technology is deployed in a HEP experiment.
The PXD is in operation as part of the Belle II experiment at KEK since March 2019 and is taking data with very good performance meeting the expectations. Since start of operation, the accelerator SuperKEKB reached a peak luminosity beyond 1e34 /cm2s and about 10 fb-1 have been recorded at the time writing. The final goal for the peak luminosity of the machine is 8e35 /cm2s and the pixel detector is designed to be operated at this final luminosity up to the accumulated data set of 50 ab-1.
The lessons learned during construction, commissioning, and operation of the first DEPFET based vertex detector will be presented.Speaker: Felix Mueller (DESY Hamburg)
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119
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Detectors for Future Facilities (incl. HL-LHC), R&D, Novel Techniques: Session I - PremiereConvener: Petra Merkel (Fermi National Accelerator Lab. (US))
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140
The CMS Tracker Upgrade for the High Luminosity LHC
The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about $5-7.5\times10^{34}$cm$^{-2}$s$^{-1}$, to possibly reach an integrated luminosity of $3000-4000\;$fb$^{-1}$ over about a decade. This High Luminosity LHC scenario, HL-LHC, starting in 2027, will require an upgrade program of the LHC detectors known as Phase-2 upgrade. The current CMS Outer Tracker, already running beyond design specifications, and CMS Phase-1 Pixel Detector will not be able to survive HL-LHC radiation conditions and CMS will need completely new devices, in order to fully exploit the highly demanding conditions and the delivered luminosity. The new Outer Tracker should have also trigger capabilities. To achieve such goals, R\&D activities have explored options for both the Outer Tracker and for the Inner Tracker. The solutions developed will allow to include tracking information in the first level trigger stage. The design choices for the Tracker upgrades are discussed along with some highlights on technological approaches and R\&D activities.
Speaker: Katja Klein (RWTH, I. Physik. Inst.) -
141
ATLAS ITk Pixel Detector Overview
For the HL-LHC upgrade the current ATLAS Inner Detector is replaced by an all-silicon system. The Pixel Detector will consist of 5 barrel layers and a number of rings, resulting in about 14 m2 of instrumented area. Due to the huge non-ionizing fluence (1e16 neq/cm2) and ionizing dose (5 MGy), the two innermost layers, instrumented with 3D pixel sensors (L0) and 100μm thin planar sensors (L1) will be replaced after about 5 years of operation. All hybrid detector modules will be read out by novel ASICs, implemented in 65nm CMOS technology, with a bandwidth of up to 5 Gb/s. Data will be transmitted optically to the off-detector readout system. To save material in the servicing cables, serial powering is employed for low voltage. Large scale prototyping programs are being carried out by all sub-systems. The talk will give an overview of the layout and current status of the development of the ITk Pixel Detector.
Speaker: Stefano Terzo (IFAE Barcelona (ES)) -
142
The ATLAS ITk Strip Detector System for the Phase-II LHC Upgrade
The ATLAS experiment at the Large Hadron Collider is currently preparing for a major upgrade of the Inner Tracking for the Phase-II LHC operation (known as HL-LHC), scheduled to start in 2026. In order to achieve the integrated luminosity of 4000 fb-1, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. The radiation damage at the full integrated luminosity implies integrated hadron fluencies over 2x10^16 neq/cm2 requiring a complete replacement of the existing Inner Detector. An all-silicon Inner Tracker (ITk) is under development with a pixel detector surrounded by a strip detector, aiming to provide increased tracking coverage up to |η|=4.
The ITk Strip Detector system consisting of four barrel layers in the centre and forward regions composed of six disks at each end, is described in the ATLAS Inner Tracker Strip Detector Technical Design Report (TDR). With the recent completion of Final Design Reviews (FDRs) in a number of key areas, such as Sensors, Modules, ASICs and Front-end electronics, the prototyping phase has been completed successfully. The pre-production phase is about to start at the institutes involved.
In this contribution we present an overview of the ITk Strip Detector System, including the final layout of the ITk Strip Detector System, and highlight the final design choices of sensors, module designs and ASICs. We will give an extended summary of the R&D results achieved in the prototyping phase. Some of the modules were irradiated with a range of fluencies and reaching up to and in some cases exceeding HL-LHC doses, demonstrating the excellent radiation hardness achieved. In addition, we will outline the current status of pre-production on various detector components, with an emphasis on QA and QC procedures. We will also discuss the status of preparations and the plans for the forth- coming pre-production and production phase.Speaker: Dennis Sperlich (Albert Ludwigs Universitaet Freiburg (DE)) -
143
The LHCb VELO Upgrade Programme for High Luminosity running at the LHC and HL-LHC
The detector currently under construction is designed to run throughout Run 3 and 4, after which a further major Upgrade will be implemented to enable the LHCb Upgrade II physics goals. The Upgrade II detector is designed to run at instantaneous luminosities of 2 × $10^{34}cm^{-2}s^{-1}$, an order of magnitude above Upgrade I, and accumulate a sample of more than 300 fb-1. At this intensity, the mean number of visible proton- proton interactions per crossing would be 56, producing around 2500 charged particles within the LHCb acceptance. The Upgrade II programme is reliant on an efficient and precise vertex detector (VELO). This subdetector enables real time reconstruction of tracks from all LHC bunch crossings in the software trigger system. The Upgrade II luminosity poses significant challenges which necessitate the construction of a new VELO with enhanced capabilities. Compared to Upgrade I there will be a further order of magnitude increase in data output rates accompanied by corresponding increases in radiation levels and occupancies. To cope with the large increase in pile-up, new techniques to assign correctly each b hadron to the primary vertex from which it originates, and to address the challenge of real time pattern recognition, are needed. These challenges will be met by the development of a new 4D hybrid pixel detector with enhanced rate and timing capabilities in the ASIC and sensor. Improvements in the mechanical design of the Ugrade II VELO will also be needed to allow for periodic module replacement. The design will be further optimised to minimise the material before the first measured point on a track (which is dominated by the secondary vacuum enclosure) and to achieve a more fully integrated module design with thinned sensors and ASICs combined with a lightweight cooling solution. It is envisaged that the readout ASIC will follow the VeloPix /Timepix4 development path with a novel design will including in-pixel timing and calibration, allowing the pixel time stamps to reach a precision of 10s of picoseconds, and a new custom output serialiser will be included. The R&D programme will explore the capabilities of combining fast timing information with small pixel size, and examine clock distribution issues for fine timing over a full system. The capabilities of the sensor to deliver fast timing will be explored for different sensor designs. The needs of the Upgrade II VELO will be outlined, along with the R&D steps envisaged to achieve the goal of a 4D pixel tracker.
Speaker: Timothy David Evans (CERN) -
144
ALICE upgrades for LHC Run 4 and beyond
While ALICE is currently undergoing major upgrades which will come online for LHC Run 3 (starting in 2021), further projects are already on their way. ALICE is developing thinned wafer-sized monolithic active pixel sensors to replace the inner tracking layers in the Long Shutdown 3 (starting in 2025). This resulting detector will have an unprecedentedly low material budget, and consequently drastically reduced interaction probabilities and unparalleled vertexing performance. Furthermore, we will present the plans for the installation of a Forward Calorimeter (FoCal) comprising a Si-W electromagnetic calorimeter with pad and pixel readout and a hadronic calorimeter with conventional metal-scintillator technology with optical readout, covering 3.4 < eta < 5.8. Finally, we will present ideas for a thin, light, fast detector fully based on silicon sensors for tracking, time-of-flight and shower measurements. This combines the advantages of extremely low material budget, fast read-out and high resolution which will enable novel measurements of electromagnetic and hadronic probes of the QGP at very low momentum.
Speaker: Andrea Rossi (Universita e INFN, Padova (IT)) -
145
Level-1 Track Finding at CMS for the HL-LHC
The success of the CMS physics program at the HL-LHC requires maintaining sufficiently low trigger thresholds to select processes at the electroweak scale. With an average expected 200 pileup interactions, critical to achieve this goal while maintaining manageable trigger rates is in the inclusion of tracking information in the Level-1 (L1) trigger. A 40 MHz silicon-based track trigger on the scale of the CMS detector has never before been built; it is a novel handle, which in addition to maintaining trigger rates can enable entirely new physics studies.
The main challenges of reconstructing tracks in the L1 trigger are the large data throughput at 40 MHz and the need for a trigger decision within 12.5 µs. To address these challenges, the CMS outer tracker for HL-LHC uses modules with closely-spaced silicon sensors to read out only the hits compatible with charged particles above 2-3 GeV ("stubs"). These are used in the back-end L1 track finding system, implemented using commercially available FPGA technology. The ever-increasing capability of modern FPGAs combined with their programming flexibility are ideal for implementing fast track finding algorithms. The proposed reconstruction algorithm forms track seeds ("tracklets") from pairs of stubs in adjacent layers of the outer tracker. These seeds provide roads where consistent stubs are included to form track candidates. Track candidates sharing multiple stubs are combined prior to being fitted. A Kalman Filter track fitting algorithm is employed to identify the final track candidates and determine the track parameters. The system is divided into nine sectors in the r-phi plane, and time-multiplexed by a factor of 18, so that each event in one sector is processed by a dedicated track finding board.
This presentation will discuss the CMS L1 track finding algorithm and its implementation, present simulation studies of estimated performance, and show recent results from a scalable system demonstrator based on prototype hardware.
Speaker: Andrew Evan Hart (Rutgers University) -
146
The CMS Trigger system for the HL-LHC
The CMS experiment has been designed with a two-level trigger system: the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger, a streamlined version of the CMS oeconstruction software running on a computer farm. During its “Phase 2” the LHC will reach a luminosity of 7X10^34 cm-2 sec-1 with a pileup of 200 collisions, integrating more than 3000 fb-1 over the full experimental run. To fully exploit the higher luminosity, the CMS experiment will introduce a more advanced Level 1 Trigger and increase the full readout rate from 100 kHz to 750 kHz. The higher luminosity, event complexity and input rate present an unprecedented challenge to the High Level Trigger, that aims to achieve a similar efficiency and rejection factor as today despite the higher pileup and more pure preselection. The ongoing studies and prospects for the online reconstruction and selection algorithms will be discussed.
Speaker: Alexandre Zabi (LLR, Ecole Polytech., IN2P3-CNRS) -
147
Precision Luminosity Measurement with the CMS detector for HL-LHC
The High Luminosity upgrade of the LHC (HL-LHC) is foreseen to increase the instantaneous luminosity by a factor of five to seven times the LHC nominal design value. The resulting, unprecedented requirements for background monitoring and luminosity measurement create the need for new high-precision instrumentation at CMS, using radiation hard detector technologies. This contribution presents the strategy for bunch-by-bunch online luminosity measurement based on various detector technologies. A main component of the system is the Tracker Endcap Pixel Detector (TEPX) with an additional 75 kHz of dedicated triggers for online measurement of luminosity and beam-induced background. Real-time implementations of algorithms such as pixel cluster counting on an FPGA are explored for online processing of the resulting data. The potential of the exploitation of the Outer Tracker, the Hadron Forward calorimeter and muon trigger objects will also be discussed.
Speaker: Gabriella Pasztor (Eotvos Lorand University) -
148
Development of a System for Abort and Luminosity of the ATLAS Experiment at the HL-LHC based on polycrystalline CVD diamond
The High Luminosity upgrade of Large Hadron Collider (HL-LHC) will increase LHC Luminosity by an order of magnitude increasing the density of particles on the detector by an order of magnitude. For protecting the inner detectors of experiments and for monitoring the delivered luminosity, a radiation hard beam monitor is being developed. We are developing a set of detectors based on poly-crystalline Chemical Vapor Deposition (pCVD) diamonds and a dedicated ASIC. Due to the large range of particle flux through the detector, flexibility is very important. To satisfy the constraints imposed by the HL-LHC, our solution is based on segmenting each single diamond sensor into multiple devices of varying size and reading them out with a new multichannel readout chip. In this talk we describe the proposed system, present preliminary results from the first detectors fabricated using our prototype ASIC and present the noise distribution and efficiency for single MIPs.
Speaker: Prof. Marko Mikuz (Jozef Stefan Institute (SI)) -
149
Upgrade of the ATLAS Muon Trigger for the HL-LHC
The present Level-1 Muon Trigger System of the ATLAS experiment will be upgraded for the HL-LHC to the Level-0 (L0) Muon Trigger with increased trigger latency of 10 ms and output rate of 1 MHz. The longer buffers in the front-end allow for more complex processing of the data, maintaining a high trigger efficiency even at highest event rates. For this purpose, the Sector Logic (SL) boards processing data from the RPC and TGC trigger chambers, is complemented by the NSW and MDT Trigger Processors processing respectively the information from the NSW trigger chambers and the MDT precision tracking chambers. To operate the future L0 Muon Trigger, the entire front-end electronics for the RPC, TGC and MDT chambers will be upgraded to cope with required rates and latencies. All RPC and TGC hit data will be transmitted from the front-end boards to the SL and the MDT hits to the MDT Trigger processors in a trigger-less mode over high-speed optical links. The low-resolution coordinates of the muon track hits supplied by the RPC, TGC and NSW trigger chambers will be used as a seed for the MDT Trigger Processors. These seeds provide Regions of Interest (RoIs) and bunch crossing identification. The MDT Trigger Processor assigned to a given sector of MDT chambers then only considers the MDT hits in a RoI, allowing for a large reduction of the relevant data volume. Hits in a RoI, together with the coarse track direction supplied by the trigger chambers, are fed to the MDT Trigger Processor to reconstruct a muon track segment in each MDT chamber and combine the segments into a muon track with significantly improved transverse momentum resolution. The much higher accuracy of the MDT hit coordinates (~0.1 mm) compared to the ones supplied by the primary trigger chambers (20-30 mm), leads to a reduction of the single muon trigger rate by about a factor 3. The MDT Trigger Processor returns the measured pT to the SL for the final muon trigger decision. Upon a L0 trigger accept, it also transmits the MDT hits to the read out system (FELIX) for the final storage. The realisation of the MDT Trigger Processor imposes several technical challenges. To maintain the latency budget, the communication with MDT front-end electronics, the SL and the read out system must be performed via a large number high-speed optical links. The identification of track segments in the RoI also needs fast processors and firmware, which is robust against all possible hit patterns. A hardware demonstrator of the MDT Trigger Processor, based on state-of-the-art FPGA and SoC technology, is currently under production. It is implemented as an ATCA board consisting of two separate modules, the Service Module responsible for the board infrastructure and the Command Module for the data processing. The presentation will cover the description of the new L0 Muon Trigger System and the status of the firmware and hardware development for MDT Trigger Processors.
Speaker: Dr Davide Cieri (Max-Planck-Institut fur Physik (DE)) -
6:00 PM
Coffee break
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150
Test-beam performance of a TORCH prototype module
The TORCH time-of-flight detector is designed to provide a 15 ps timing resolution for charged particles, resulting in K/pi (p/K) particle identification up to 10 (15) GeV/c momentum over a 10 m flight path. Cherenkov photons, produced in a quartz plate of 10 mm thickness, are focused onto an array of micro-channel plate photomultipliers (MCP-PMTs) which measure the photon arrival times and spatial positions. A half-scale (660 x 1250 x 10 mm^3) TORCH demonstrator module instrumented with customised MCP_PMTs has been tested in a 5 GeV/c mixed proton-pion beam at the CERN PS. The MCP-PMTs with the active area 53 x 53 mm^2 and granularity 64 x 8 pixels have been developed in collaboration with an industrial partner (Photek). With 30 photons per particle detected, the 15 ps per particle time resolution requires single-photon resolution of 70 ps. The timing performance and photon yields have been measured as a function of beam position in the radiator, giving measurements which are consistent with expectations. A possible TORCH design of the particle identification system in the LHCb experiment has been simulated and the potential for particle identification performance for high luminosity running has been evaluated.
Speaker: Michal Kreps (University of Warwick (GB)) -
151
A High-Granularity Timing Detector for the Phase-II upgrade of the ATLAS Calorimeter system: detector concept, description and R&D and beam test results
The increase of the particle flux (pile-up) at the HL-LHC with luminosities of L ≃ 7.5 × 10^34 cm−2s−1 will have a severe impact on the ATLAS detector reconstruction and trigger performance. The end-cap and forward region where the liquid Argon calorimeter has coarser granularity and the inner tracker has poorer longitudinal vertex position resolution will be particularly affected. A High Granularity Timing Detector (HGTD) is proposed in front of the LAr end-cap calorimeters for pile-up mitigation and for luminosity measurement.
It will cover the pseudo-rapidity range from 2.4 to 4.0. Two Silicon sensors double sided layers will provide precision timing information for MIPs with a resolution better than 30 ps per track in order to assign each particle to the correct vertex. Readout cells have a size of 1.3 mm × 1.3 mm, leading to a highly granular detector with 3 millions of channels. Low Gain Avalanche Detectors (LGAD) technology has been chosen as it provides enough gain to reach the large signal over noise ratio needed. A dedicated ASIC is being developed and some prototypes have been already submitted and measured.
The requirements and overall specifications of the HGTD will be discussed. LGAD R&D campaigns are carried out to study the sensors, the related ASICs, and the radiation hardness. Laboratory and test beam results will be presented.
Speaker: Chiara Rizzi (CERN) -
152
Development of the CMS MTD Endcap Timing Layer for HL-LHC
The MIP Timing Detector (MTD) of the Compact Muon Solenoid (CMS) is designed to provide precision timing information (with resolution of ~40 ps per layer) for charged particles, with hermetic coverage up to a pseudo-rapidity of |η|=3. This upgrade will reduce the effects of pileup expected under the High-Luminosity LHC (HL-LHC) running conditions and brings new and unique capabilities to the CMS detector. The time information assigned to each track will enable the use of 4D reconstruction algorithms and will further discriminate in the time domain interaction vertices within the same bunch crossing to recover the track purity of vertices in current LHC conditions. The endcap region of the MTD, called the Endcap Timing Layer (ETL), will be instrumented with silicon-based low gain avalanche detectors (LGADs), covering the high radiation pseudo-rapidity region between |η|=1.6 and 3.0. Each endcap will be instrumented with a two-disk system of LGADs, read out by Endcap Timing Readout Chips (ETROCs), being designed for precision timing measurements. We will go over the motivations for the MTD and will present an overview of the MTD ETL design. We will also present the R&D and test beam studies that were integral for achieving the ETL design, as well as recent progress on the development of the ETROC readout electronics.
Speaker: Karri Folan Di Petrillo (Fermi National Accelerator Lab.) -
153
Precision Timing with the CMS MTD Barrel Timing Layer for HL-LHC
The Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider (LHC) is undergoing an extensive Phase II upgrade program to prepare for the challenging conditions of the High-Luminosity LHC (HL-LHC). A new timing detector in CMS will measure minimum ionizing particles (MIPs) with a time resolution of ~30-40 ps and hermetic coverage up to a pseudo-rapidity of |η|=3. The precision time information from this MIP Timing Detector (MTD) will reduce the effects of the high levels of pileup expected at the HL-LHC, enhancing and expanding the physics reach of the CMS detector. For instance, in the analysis of di-Higgs boson production, a timing resolution of 30-40 ps is expected to improve the effective luminosity by about 25% through gains in b-tagging and isolation efficiency. The central Barrel Timing Layer (BTL) will be based on LYSO:Ce crystals read out with silicon photomultipliers (SiPMs). The BTL will use elongated crystal bars, with double-sided read out (a SiPM on each end of the crystal), in order to maximize detector performance within the constraints of space, cost, and channel count. We will present an overview of the MTD BTL design, highlighting some of physics analyses impacted by the MTD. We will review the extensive R&D studies carried out to optimize the BTL design and the test beam results in which the goal of 30 ps timing resolution has been achieved.
Speaker: Nan Lu (California Inst. of Tech.) -
154
The CMS Phase-2 high-granularity 5D calorimeter
The CMS high-granularity endcap calorimeter (HGCAL) is a challenging detector that brings together tracking and calorimetry, silicon and scintillators, as well as linear collider detector concepts, to meet the harsh radiation and pileup environment of the High Luminosity LHC Phase (Phase 2) in the forward region and exploit challenging signatures such as VBF/VBS production. The HGCAL features unprecedented transverse and longitudinal segmentation in both its electromagnetic (ECAL) and hadronic (HCAL) compartments. This information allows to resolve the fine structure of showers, playing to the strengths of particle-flow reconstruction, and allowing to enhance pileup rejection and particle identification, while still achieving good energy resolution. The ECAL and a large fraction of HCAL will be based on hexagonal silicon sensors of 0.5 - 1 cm^{2} cell size. The remainder of the HCAL will be based on highly-segmented scintillators read out by silicon photo-multipliers (SiPM). The intrinsic high-precision timing capabilities of the silicon sensors add a further measurement dimension, critical in event reconstruction, especially for pileup rejection. This presentation will overview the HGCAL project, covering the physics motivation, engineering design, readout and trigger concepts, performance (simulated and from beam tests), as well as ways in which the 5D information content may be exploited by cutting-edge machine learning techniques to enhance the overall physics performance of the forward region.
Speaker: Jeremy Mans (University of Minnesota (US)) -
155
Paving the way to reconstruct the 5D information of the CMS HGCAL detector at the HL-LHC
To maintain and improve physics performance under the harsher conditions of the high luminosity LHC phase from 2026, the CMS collaboration has designed a novel endcap calorimeter that uses silicon sensors to achieve radiation tolerance, with the additional benefit of a very high readout granularity. In regions characterised by lower radiation levels, small scintillator tiles with individual SiPM readout are employed. A novel reconstruction approach is being developed to fully exploit the granularity and other significant features of the detector like precision timing, with a view to deployment in the high pileup environment of HL-LHC. An iterative reconstruction framework (TICL) has been put in place, and is being actively developed. The inputs to the framework are clusters of energy deposited in individual calorimeter layers delivered by a density-based algorithm which has recently been developed and tuned. In view of the expected pressure on the computing capacity in the HL-LHC era, the algorithms and their data structured are being designed with GPUs in mind. Preliminary results show that significant speed-up can be obtained running the clustering algorithm on GPUs. In addition, machine learning techniques based on cutting-edge techniques are being investigated and integrated into the reconstruction framework. This talk will describe the approaches being considered and show first results.
Speaker: Jingyu Zhang (Florida State University (US)) -
156
The CMS Muon Spectrometer Upgrade
The luminosity delivered to the experiments by the High Luminosity Large Hadron Collider (HL-LHC) is expected to be at least five times the original design, exceeding the value of 5 × 10^34 cm^−2 s^−1. The detectors will therefore undergo critical upgrades to sustain the higher particle fluxes and improve the tracking and triggering performance. In the current CMS muon system, different detector technologies have been chosen to optimize the CMS detector with respect to performance. Drift Tubes (DT) and Resistive Plate Chambers (RPC) are installed in the barrel, complemented by the two endcaps hosting cathode strip chambers (CSC) and RPC. The upgrade of the Muon Spectrometer will act on the improvement of the electronics installed on DT and CSC and on the extension of the coverage with the installation of additional muon stations in the endcaps - ME0, GE1/1, GE2/1, RE3/1 and RE4/1. Due to the extended lifetime now expected of the LHC experiments (2008-2040) and the significantly larger integrated luminosity accumulated, additional aging tests are required and taking place for the existing muon detectors. The CSC electronics upgrade is planned to take place during the current Long Shutdown 2 (LS2) and is almost completed. The electronics upgrade of the DT is planned for LS3; currently, a slice test exercise is installed and giving the first results. The production, qualification and installation of GE1/1 detectors has completed in spring 2020, followed by the ongoing commissioning in the CMS experiment. The production of GE2/1 is about to start, while the R&D for ME0 and improved RPC (iRPC) is now in the final phase. The presentation will give an overview of the Muon Spectrometer upgrades, describing the aging studies conducted and the frontend on-chamber electronics developments for the DT and CSC. We will provide an overview on the design of GEM and iRPC detectors, as well as a detailed report on the preliminary results obtained during the production, qualification, installation and commissioning of GE1/1 in CMS.
Speaker: Daniele Fasanella (CERN) -
157
Upgrade of the CMS Cathode Strip Chambers for the HL-LHC
The Large Hadron Collider (LHC) will be upgraded in several phases to significantly expand its physics program, and these upgrades present major challenges to the operations of the CMS cathode-strip-chamber muon system. After the current long shutdown from 2018-2020 (LS2) the accelerator luminosity will be increased to 2 − 3 10^34cm{−2}s{−1}, exceeding the design value of 10^{34}cm^{−2}s^{−1}, allowing the CMS experiment to collect approximately 100 fb^{−1}/year. A subsequent upgrade in 2022-23 will increase the luminosity up to 5 10^{34} cm^{−2}^{s−1}. The CMS muon system must be able to sustain a physics program after the LS2 shutdown that maintains sensitivity to electroweak scale physics and for TeV scale searches similar to what was achieved up to now For the Cathode Strip Chamber (CSC) muon detectors, the electronics will be upgraded to handle the expected higher data rates. The design of the upgraded CSC electronics will be discussed as well as the status of the first phase of the electronics installation. In addition, accelerated irradiation tests are being performed to study the behavior of the CSC electronics under conditions which are nearly an order of magnitude beyond the original design values. Studies have also been performed of chamber gas mixtures to reduce greenhouse-gas impacts. The status of this irradiation campaign and results will be presented.
Speaker: Sven Dildick (Rice Univ.) -
158
Upgrade of the ATLAS Muon Drift Tube (MDT) electronics for HL-LHC runs
The ATLAS monitored drift tube (MDT) chambers are the main component of the precision tracking system in the ATLAS muon spectrometer. The MDT system is capable of measuring the sagitta of muon tracks to an accuracy of 60 μm, which corresponds to a momentum accuracy of about 10% at pT=1 TeV. To cope with large amount of data and high event rate expected from the High-Luminosity LHC (HL-LHC) upgrade, ATLAS plans to use the MDT detector at the first-trigger level to improve the muon transverse momentum resolution and reduce the trigger rate. The new MDT trigger and readout system will have an output event rate of 1 MHz and a latency of 6 us at the first-level trigger. A new trigger and readout system has been proposed. Prototypes for two frontend ASICs and a data transmission board have been designed and tested, and detailed simulation of the trigger latency has been performed. We will present the overall design of the trigger and readout system and focus on latest results from different ASIC and board prototypes and system integration.
Speaker: Xueye Hu (University of Michigan (US))
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140
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Computing and Data Handling: Session I - PremiereConveners: Elisabetta Maria Pennacchio (Centre National de la Recherche Scientifique (FR)), Dagmar Adamova (Czech Academy of Sciences (CZ))
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159
Application of Quantum Machine Learning to High Energy Physics Analysis at LHC using IBM Quantum Computer Simulators and IBM Quantum Computer Hardware
Using IBM Quantum Computer Simulators and Quantum Computer Hardware, we have successfully employed the Quantum Support Vector Machine Method (QSVM) for a ttH (H to two photons), Higgs production in association with a top quark pair analysis at the LHC.
We will present our experiences and results of a study on LHC high energy physics data analysis with IBM Quantum Computer Simulators and IBM Quantum Computer Hardware using IBM Qiskit. The work is in the context of a Qubit platform. Taking into account the limitation of a low number of qubits, the result using the Quantum Computer Simulators expressed in a ROC curve is comparable with the results using classical machine learning methods (BDT and classical SVM). This study is applied to a ttH physics analysis, one of the flagship physics channels at the LHC, with 5 qubits, 100 training events and 100 test events. Here the ROC curve is defined as the Receiver Operating Characteristics curve in the plane of background rejection versus signal efficiency.
In addition, we have employed the IBM QSVM Variational quantum machine learning algorithm using 5 qubits on the IBM Quantum Computer Hardware of 20 qubits (“IBM Boeblingen”), with 100 training events and 100 test events, again for a ttH (H to two photons) analysis at the LHC. The present result from the IBM Quantum Hardware is about 10% in performance below the Quantum Simulation.
The work is performed by an international and interdisciplinary collaboration with Department of Physics and Department of Computer Sciences of University of Wisconsin, CERN Openlab of IT Division, IBM Research Zurich and Fermilab Quantum Institute.
This work pioneers a close collaboration of academic institutions with industrial corporations in a High Energy Physics analysis effort.
Speaker: Chen Zhou (University of Wisconsin Madison (US)) -
160
On the impact of modern deep-learning techniques to the performance and time-requirements of classification models in experimental high-energy physics
Beginning from a basic neural-network architecture, we test the potential benefits offered by a range of advanced techniques for machine learning and deep learning in the context of a typical classification problem encountered in the domain of high-energy physics, using a well-studied dataset: the 2014 Higgs ML Kaggle dataset. The advantages are evaluated in terms of both performance metrics and the time required to train and apply the resulting models. Techniques examined include domain-specific data-augmentation, learning rate and momentum scheduling, (advanced) ensembling in both model-space and weight-space, and alternative architectures and connection methods. Following the investigation, we arrive at a model which achieves equal performance to the winning solution of the original Kaggle challenge, whilst requiring about 2% of the training time and less than 5% of the inference time using much less specialised hardware. Additionally, a new wrapper library for PyTorch called LUMIN is presented, which incorporates all of the techniques studied.
Speaker: Giles Chatham Strong (Universita e INFN, Padova (IT)) -
161
Hello RNTuple and friends: what the new ROOT means for your analysis
ROOT is one of HEP's most senior active software projects; virtually every physicist uses it, and its TTree is the backbone of HEP data. But ROOT can do even better - and it's getting there, step by step. It now features RDataFrame, a new, simple and super-fast way to write a data analysis. Soon TTree will have a successor, RNTuple, allowing for even faster data processing. Graphics will become web-based, sleek, and right-by-default. Python interfaces are promoted to become a first class citizen, and even histograms will see a new generation with more obvious, simpler interfaces and higher speed. This presentation will feature a sneak preview for all of this - because we do this for you, and we want your comments to get it right, for the next 30 years.
Speaker: Axel Naumann (CERN) -
4:30 PM
Coffee break
virtual conference
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162
What the new RooFit can do for your analysis
RooFit is a toolkit for statistical modelling and fitting, and together with RooStats it is used for measurements and statistical tests by most experiments in particle physics.
Since one year, RooFit is being modernised. In this talk, improvements already released with ROOT will be discussed, such as faster data loading, vectorised computations and more standard-like interfaces. These allow for speeding up unbinned fits by several factors, and make RooFit easier to use from both C++ and python.
Furthermore, an overview of features in development is given, such as a fast implementation of "HistFactory" computations, easier data loading, and the prospects for RooFit computations on GPUs.Speaker: Stephan Hageboeck (CERN) -
163
Automated selection of particle-jet features for data analysis inHigh Energy Physics experiments
In high-energy physics experiments, the sensitivity of selection-based analyses critically depends on which observable quantities are taken into consideration and which ones are discarded as considered least important. In this process, scientists are usually guided by their cultural background and by literature.
Yet simple and powerful, this approach may be sub-optimal when machine learning strategies are envisaged and potentially all features are usable. On the other hand, training multivariate algorithms with all available features is often impossible, due to lack of calibration or computing power limitations. How to robustly choose the set of observables to use in a modern high-energy physics analysis?
We show here that it is possible to rank the relative importance of all available features in an automated fashion by engineering a fast and powerful classification model.
Features are sorted with the Random Forest algorithm, then selected as input quantities for a Deep Learning Neural Network. We make it explicit the relation between Random Forest importance ranking and signal-to-background ratio increase, varying the number of features to feed the Neural Network with. We benchmark our procedure with the case of highly boosted di-jet resonances decaying to two b~quarks, to be selected against an overwhelming QCD background. Promising results from Monte Carlo simulation with HEP pseudo-detectors are shown.Speaker: Mr Andrea Di Luca (Universita degli Studi di Trento and INFN (IT)) -
164
Data Analysis with GPU-Accelerated Kernels
At HEP experiments, processing billions of records of structured numerical data can be a bottleneck in the analysis pipeline. This step is typically more complex than current query languages allow, such that numerical codes are used. As highly parallel computing architectures are increasingly important in the computing ecosystem, it may be useful to consider how accelerators such as GPUs can be used for data analysis. Using CMS and ATLAS Open Data, we implement a benchmark physics analysis with GPU acceleration directly in Python based on efficient computational kernels using Numba/LLVM, resulting in an order of magnitude throughput increase over a pure CPU-based approach. We discuss the implementation and performance benchmarks of the physics kernels on CPU and GPU targets. We demonstrate how these kernels are combined to a modern ML-intensive workflow to enable efficient data analysis on high-performance servers and remark on possible operational considerations.
Speaker: Irene Dutta (California Institute of Technology (US)) -
5:50 PM
Coffee break
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165
Parallelization for HEP Event Reconstruction
We report on developments targeting a boost in the utilization of parallel computing architectures in HEP reconstruction, particularly for LHC experiments and for neutrino experiments using Liquid Argon Time-Projection Chamber (LArTPC) detectors. Key algorithms in the reconstruction workflows of HEP experiments were identified and redesigned: charged particle track reconstruction for CMS, and hit finding for LArTPC detectors such as ICARUS and MicroBooNE. These algorithms are some of the most time-consuming steps of the event reconstruction, and optimizing their computational performance is key to defining the computing needs for the reconstruction software of the next-generation HEP experiments. With the use of advanced profiling tools and development techniques, the algorithms have been rewritten so that they can take full advantage of multi-threading and vectorization on modern multicore CPUs, while at the same time satisfying physics performance goals. On a single thread, the modified versions are faster than the original algorithms by a factor ranging from 6 to 12x, depending on the application, and both the track reconstruction and hit finder algorithms have been integrated into the experiments’ reconstruction software. Portable implementations of the algorithms for usage at supercomputers and with heterogenous platforms have been explored.
Speakers: Giuseppe Cerati (Fermi National Accelerator Lab. (US)), Allison Reinsvold Hall (Fermilab), Giuseppe Cerati (Fermi National Accelerator Lab. (US)) -
166
Using an Optical Processing Unit for tracking and calorimetry at the LHC
The High Luminosity Large Hadron Collider is expected to have a 10 times higher readout rate than the current state, significantly increasing the computational load required. It is then essential to explore new hardware paradigms. In this work we consider the Optical Processing Units (OPU) from LightOn, which compute random matrix multiplications on large datasets in an analog, fast and economic way, fostering faster machine learning results on a dataset of reduced dimension. We consider two case studies.
1) “Event classification”: high energy proton collision at the Large Hadron Collider have been simulated, each collision being recorded as an image representing the energy flux in the detector. The task is to train a classifier to separate a Susy signal from the background. The OPU allows fast end-to-end classification without building intermediate objects (like jets). This technique is presented, compared with more classical particle physics approaches.
2) “Tracking”: high energy proton collisions at the LHC yield billions of records with typically 100,000 3D points corresponding to the trajectory of 10.000 particles. Using two datasets from previous tracking challenges, we investigate the OPU potential to solve similar or related problems in high-energy physics, in terms of dimensionality reduction, data representation, and preliminary results.
Speaker: Laurent Basara (LAL/LRI, Université Paris Saclay)
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159
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Education and Outreach: Session I - PremiereConveners: Miroslav Myska (Czech Technical University (CZ)), Steven Goldfarb (University of Melbourne (AU))
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167
The International Particle Physics Outreach Group - Reaching Across the Globe with Science
The International Particle Physics Outreach Group (IPPOG) is a network of scientists, science educators and communication specialists working across the globe in informal science education and outreach for particle physics. The primary methodology adopted by IPPOG requires the direct involvement of scientists active in current research with education and communication specialists, in order to effectively develop and share best practices in outreach. IPPOG member activities include the International Particle Physics Masterclass programme, International Day of Women and Girls in Science, Worldwide Data Day, International Muon Week and International Cosmic Day organisation, and participation in activities ranging from public talks, festivals, exhibitions, teacher training, student competitions, and open days at local institutions. These independent activities, often carried out in a variety of languages to public with a variety of backgrounds, all serve to gain the public trust and to improve worldwide understanding and support of science. We present our vision of IPPOG as a strategic pillar of particle physics, fundamental research and evidence-based decision-making around the world.
Speaker: Steven Goldfarb (University of Melbourne (AU)) -
168
Current Status of International Particle Physics Masterclasses
Until recently, the International Masterclasses (IMC) in Particle Physics have been based on hands-on analysis of data from the four big LHC experiments. During the last years there has been a spectacular broadening in the physics scope of particle physics masterclasses, now including measurements with Belle II data, with data from neutrino experiments and a newly proposed masterclass on searches for dark matter. In addition, a particle therapy masterclass has been developed, in order to highlight some of the benefits for society from the technology developed for particle physics research. In parallel to extending the physics scope, IPPOG is making efforts to extend the geographical reach of masterclasses, and it is encouraging to see new institutes and countries joining each year. The IMC programme is the flagship activity of IPPOG, the International Particle Physics Outreach Group.
Speakers: Uta Bilow (Technische Universitaet Dresden (DE)), Kenneth William Cecire (University of Notre Dame (US)) -
169
Netzwerk Teilchenwelt: Coordinated Outreach and Recruitment of Young Talents in Germany
Netzwerk Teilchenwelt is a Germany-wide outreach program comprising 30 universities and research labs. About 150 researchers are involved, bringing cutting edge science into the classroom. 3500 high school students each year take the opportunity to work with original data from HEP experiments in special masterclasses or to study cosmic particles with detectors. On advanced levels, motivated students continue to engage in research and attend workshops at CERN or conduct their research projects. Through a fellow program, highly motivated students are offered early contact with research groups, personal support, and further training. Activities are funded by the German Ministry of Education and Research as an integral part of HEP research. Within the current funding scheme, topics from hadron and nuclear physics are included and links to other projects are created which expand the range of target groups.
Speaker: Uta Bilow (Technische Universitaet Dresden (DE)) -
170
Global Cosmic
Cosmic rays are a unique tool for introducing high-school students to particle physics concepts and methods; their detection and study, with a variety of cosmic ray experiments in schools, is an excellent way to acquaint them with the world of scientific research, motivate and inspire them. Cosmic-ray experiments in schools, using a variety of detector types and sizes, exist in many countries, often as part of networks, and in some cases they also produce scientific results. In order to better exploit the great potential of cosmic-ray experiments for particle physics outreach, IPPOG, the International Particle Physics Outreach Group, started an effort to put such experiments under a common umbrella; a workshop was organised in Rome in 2017 where a whole spectrum of cosmic-ray related activities in schools were represented. Global cosmics – a working group of IPPOG – follows up and reports during IPPOG meetings. Activities such as International Cosmic Day, organised by DESY and Cosmic Ray Week, organized by Quarknet are promoted and strongly encouraged by IPPOG.
Speaker: Nicolas Arnaud (LAL (CNRS/IN2P3 and Université Paris-Sud)) -
4:50 PM
Coffee Break
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171
ATLAS Virtual Visits – Take part from anywhere in the world
The Virtual Visit service run by the ATLAS Collaboration has been provided since 2010. The ATLAS Collaboration has used this popular and effective method to bring the excitement of scientific exploration and discovery into classrooms and other public places around the world. The programme, which uses a combination of video conferencing, webcasts, and video recording to communicate with remote audiences has already reached tens of thousands of viewers, with a large number of languages, from tens of countries covering the six populated continents.
We present a summary of the ATLAS Virtual Visit service that is currently in use: the booking system, the video conference that is held from the ATLAS Visit Centre and ATLAS Control Room, the possibility to make virtual tours from the ATLAS cavern, and the new system that is being installed in the ATLAS cavern to provide high-quality underground virtual visits. In addition, we show the reach of the programme over the last few years.Speaker: Ben Carlson (University of Pittsburgh) -
172
CMS Virtual Visits: engaging audiences worldwide into conversation about cutting edge science
Advances in information and communications technologies (ICTs) have given rise to innovative uses of web-based video tools for global communication, enhancing the impact of large research facilities, including their outreach and education programmes. As an example, the CMS Virtual Visits programme launched by the CMS collaborations at CERN, uses videoconferencing to communicate with schools and other public around the globe.
The goal of the programme is to break down geographical barriers and allow more people to enter the world of science, physics and particle physics. CMS Virtual Visits offer students, teachers and the general public a unique opportunity to explore the experimental site of the CMS detector. Through a web-based videoconference, CMS scientists interact with “remote" visitors in their native language, explain the physics and technology behind the CMS detector, and answer their questions.
Since September 2014, more than 35,000 people, from all of the world, have participated in CMS Virtual Visits. We present an overview of our experience, feedback collected from participants and discuss potential development for the future.
Speaker: Cecilia Uribe Estrada (Puebla) -
173
Getting the public closer to the experimental facilities: How Virtual Reality helps HEP experiments engage public interest
For many HEP experiments the experimental area is difficult to access for visitors. That makes engaging the public difficult. This is true both for educational purposes and for outreach and media events. The use of the latest technologies in Virtual Reality (VR), Augmented Reality (AR), and 360 degree visualization helps the experiments in getting the public closer to their research. By virtually entering the experimental area the public can visit the different facilities in an immersive and autonomous way; also, by getting closer to the detector, people can get a feeling of the size and the complexity of the experiment itself.
Here we will present the applications based on these technologies developed within the ATLAS Collaboration. We will show how they have been used successfully in presentations to funding agencies and in a number of public events to educate the public about the ATLAS experiment and to generally engage the public in High Energy Physics fundamental research.Speaker: Ana Peixoto (LIP Laboratorio de Instrumentacao e Fisica Experimental de Part) -
174
Development of Mixed Reality Software Applications for the ATLAS Experiment
Visualisation plays an important cognitive role in understanding and learning different facilities and processes in high energy physics experiments. It can synthesise Augmented Reality and Virtual Environment to create Mixed Reality Applications with detector descriptions and high-level interactions like gesture or touch controls, easy and minimalistic UI and Lego-like interactions with geometries, for better cognition.
Several Mixed Reality detector display applications can be considered according to user-specific requirements - (ART) - Augmented Reality Table, an application where users will be able to place the detector in the desired location and interact with geometry using a real-time hand recognition system or touch controls and select or grab different components of the detector; (ARD) Augmented Reality Door, where users can place a virtual door in a real-life environment and navigate through the facilities; (LND) Augmented reality landscape, by this application users can place full-sized detectors in real-life environments; (ARB) Augmented Reality Book, users will scan certain images in books or leaflets and see corresponding 3D objects placed on paper.
This paper represents the methods and tools for the creation of the above mentioned Augmented Reality applications.Speaker: Mariam Pirtskhalava (Georgian Technical University (GE)) -
175
The ATLAS public website - Evolution to Drupal 8
Four years after the deployment of the ATLAS public website using the Drupal 7 content management system, the ATLAS Education & Outreach group is in the process of migrating to the new CERN Drupal 8 infrastructure. We present lessons learned from the development, usage and evolution of the original web site, and how the choice of technology helped to shape and reinforce our communication strategy. We then discuss tactics for the migration to Drupal 8, including our choice to use the CERN Override theme. This theme was developed by the CERN web team to support clients like ATLAS to develop web sites in the relatively complex and non-intuitive environment of Drupal. Furthermore, CERN has encouraged usage of this theme to mitigate support and ease future migration. We present the effects this choice has on the design, implementation, operation and maintenance of the new site.
Speaker: Meirin Oan Evans (University of Sussex (GB))
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167
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Neutrino Physics: Session I - Replay
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Beyond the Standard Model: Session I - Replay
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Top Quark and Electroweak Physics: Session I - Replay
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Quark and Lepton Flavour Physics: Session I - Replay
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Strong Interactions and Hadron Physics: Session I - Replay
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Heavy Ions: Session I - Replay
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Astro-particle Physics and Cosmology: Session I - Replay
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Dark Matter Detection: Session I - Replay
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Operation, Performance and Upgrade of Present Detectors: Session I - ReplayConvener: Jiri Kroll (Czech Academy of Sciences (CZ))
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Detectors for Future Facilities (incl. HL-LHC), R&D, Novel Techniques: Session I - Replay
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Computing and Data Handling: Session I - Replay
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Education and Outreach: Session I - Replay
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Higgs Physics - Posters: Block IConveners: Julie Malcles (Université Paris-Saclay (FR)), Jiri Hejbal (Czech Academy of Sciences (CZ))
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176
Search for Higgs boson in the final state with two leptons and a photon produced in pp collisions at a center-of-mass energy of 13 TeV with the ATLAS detector
A search for decays of the Higgs boson in the final state with two leptons (electrons or muons) and a photon produced in pp collisions at a center-of-mass energy of 13 TeV with the ATLAS detector is presented. Estimates of Higgs boson signal and background contributions are performed for the three-body invariant mass distribution of the di-lepton plus photon system. Background estimates and corresponding systematic uncertainties are shown. Expected and observed limits on the corresponding Higgs boson cross-section are presented.
Speaker: Artem Basalaev (Deutsches Elektronen-Synchrotron (DE)) -
177
Measurement of Higgs boson production at high momentum in the VH, H → bb channel with the ATLAS detector
With the rapidly increasing proton-proton collision data-set recorded by the ATLAS experiment at the LHC, one gains access to Higgs bosons produced with ever higher transverse momenta. Measurements in this phase space are well motivated by a vast variety of BSM models which predict effects that scale with the square of the involved energy scale. The associated production of a Higgs boson H with a heavy vector boson V allows to probe the HVV interaction at high momentum scales. Combining this production mode with the most prominent decay into a pair of bottom quarks promises a large enough signal yield in this rare topology. Requiring the vector boson to further decay leptonically ensures a clean detector signature to separate signal from background. A measurement of the production cross section times the decay branching fraction of the Higgs boson into two b-quarks will be presented, based on data collected at a center-of-mass energy of 13 TeV.
Speakers: Brian Moser, Brian Moser (Nikhef National institute for subatomic physics (NL)) -
178
Searching for lepton-flavour-violating decays of the Higgs boson with the ATLAS detector
The observation of neutrino oscillations indicates that lepton flavour violation (LFV) occurs in nature and that lepton flavour is not an exact symmetry. However, no observation has been made in the charged sector, which would be a clear indication of physics Beyond the Standard Model (BSM). There are BSM models which predict LFV decays of the Higgs boson into a pair of leptons with different flavours such as models with more than one Higgs doublet, composite Higgs models, models with flavour symmetries, Randall–Sundrum models and many more. In this poster we present the search for Higgs Bosons decaying into a tau lepton and either an electron or a muon, using data collected by the ATLAS detector at a centre-of-mass energy of 13 TeV. The searches for H->e tau and H->mu tau decays were performed independently and in both cases, the search was split into cases where the tau lepton decayed leptonically or hadronically. Multivariate techniques were used in this search to discern the LFV signal from the SM background. The achieved results will be discussed in this poster.
Speaker: Julia Iturbe (The Chinese University of Hong Kong (HK)) -
179
Search for new resonances in high-mass diphoton final states using proton-proton collision data collected with the ATLAS detector
Since the discovery of the 125 GeV Higgs boson at the LHC, studies of the Higgs sector have become an important topic of the ATLAS physics program. There are many potential extensions of the Standard Model (SM) that predict new high-mass states decaying into two photons. Among which, two types of signal models are considered: a spin-0 resonance which was predicted in theories with an extended Higgs sector such as the two-Higgs doublet models (2HDM), and a spin-2 graviton excitation of a Randall-Sundrum model with one warped extra dimension. The diphoton final state played an important role when the H(125) Higgs boson was discovered, and is chosen for this search as it provides a clean experimental signature with excellent invariant mass resolution and moderate backgrounds. This poster presents the search for new resonances decaying into two photons, using pp collisions collected with the ATLAS detector at LHC at a centre-of-mass energy of 13 TeV. Pairs of isolated photon candidates with high invariant masses are selected. The results of this search will be discussed in this poster.
Speaker: Yufeng Wang -
180
Search for Invisibly Decaying Vector Boson Fusion Produced Higgs Bosons with 139/fb of pp collisions with the ATLAS Detector
While the Standard Model (SM) predicts a branching ratio of the Higgs boson decaying to invisible particles of O(0.001), the current measurement of the Higgs boson coupling to other SM particles allows for up to 30% of the Higgs boson width to originate from decays beyond the SM (BSM). The small SM-allowed rate of Higgs boson decays to invisible particles can be enhanced if the Higgs boson decays into a pair of weakly interacting massive particles (WIMPS), which may explain the nature of dark matter. The Vector Boson Fusion (VBF) production mechanism of the Higgs boson provides a distinctive signature (with two forward jets that are largely separated in pseudorapidity leading to a large invariant mass) that can be used to target events with invisible Higgs decays, where particles invisible to the detector are a source of missing transverse energy. The most recent ATLAS results of VBF-produced Higgs bosons decaying invisibly are presented, utilizing the full Run-2 dataset of 139/fb of 13 TeV center-of-mass proton--proton collisions. Further interpretations set limits on the VBF production of other heavy scalars, and the WIMP-nucleon cross-section.
Speaker: Amanda Lynn Steinhebel -
181
Search for lepton flavour violating decays of the Higgs boson with Run II data
A search for lepton flavour violating (LFV) decays of the Higgs boson to a muon and a tau, denoted as $\mu\tau$ and an electron and a tau, denoted as $e\tau$ will be presented. A dataset of $137 fb^{-1}$ of proton-proton collisions collected by the CMS detector in Run II, at a center-of-mass energy of $\sqrt{s}=13TeV$ is being used to perform the search. The dominant background contributions for this search are coming from the Drell-Yan process, misidentified leptons, and the top-quark pair-production process. We are using data-driven techniques to estimate the majority of the background. In our previous search using 2016 data, we set the observed (expected) upper limits on the LFV branching fractions of the Higgs boson to be $B(H \to \mu \tau) < 0.25 \% (0.25\%)$ and $B(H \to e \tau) < 0.61\% (0.37\%)$, at $95\%$ confidence level. With the current search, we anticipate setting the most stringent limits to date on these branching fractions using the full Run II data.
Speakers: Lourdes Urda (CIEMAT (Madrid)), Prasanna Kumar Siddireddy (University of Notre Dame (US))
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176
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Neutrino Physics - Posters: Block IConvener: Jaroslav Zalesak (Czech Academy of Sciences (CZ))
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182
Collective neutrino oscillations accounting for neutrino quantum decoherence
The effect of neutrino quantum decoherence has attracted a growing interest during the last 15 years. Most of already performed corresponding studies deal with searches of neutrino quantum decoherence in terrestrial reactor and solar neutrino experiments (see, for example, [1]). The forthcoming new large volume neutrino detectors (e.g. JUNO, DUNE and Hyper-Kamiokande), will provide a new frontier in high-statistics measurements of neutrino fluxes from supernovae that will give a new opportunity to study the effect of neutrino quantum decoherence also in supernovae fluxes. In [2-4] we suggested a new mechanism of neutrino quantum decoherence in the supernovae due to the neutrino interaction with external environment and showed that it becomes significant in the region where the collective neutrino oscillations occur. In this work we are presenting our new results on the numerical calculations of collective neutrino oscillations in supernovae accounting for the neutrino quantum decoherence and study the possibility to detect the effect of neutrino quantum decoherence in supernovae neutrino fluxes in the future terrestrial experiments.
[1] J.A.B.Coelho, W.A.Mann, S.S.Bashar, Phys.Rev.Lett. 118 (2017) 221801.
[2] K.Stankevich, A.Studenikin, PoS ICHEP2018 (2019) 925.
[3] K.Stankevich, A.Studenikin, arXiv:1912.13313.
[4] K.Stankevich, A.Studenikin “Neutrino quantum decoherence engendered by neutrino radiative decay”, arXiv:submit/3035045 [hep-ph] 7 Feb 2020, accepted for publishing in Phys.Rev.D.Speaker: Konstantin Stankevich (Lomonosov Moscow State University) -
183
0νββ in left-right theories with Higgs doublets and gauge coupling unification
We consider a version of Left-Right Symmetric Model in which the scalar sector consists of a Higgs bidoublet ($\Phi$) with $B-L=0$, Higgs doublets ($H_{L,R}$) with $B-L=1$ and a charged scalar ($\delta^+$) with $B-L=2$ leading to radiatively generated Majorana masses for neutrinos and thereby, leads to new physics contributions to neutrinoless double beta decay ($0\nu \beta \beta$). We show that such a novel framework can be embedded in a non-SUSY $SO(10)$ GUT leading to successful gauge coupling unification at around $10^{16}$GeV with the scale of left-right symmetry breaking around $10^{10}$GeV. The model can also be extended to have left-right symmetry breaking at TeV scale, enabling detection of $W_R, Z_R$ bosons in LHC and future collider searches. In the context of neutrinoless double beta decay, this model can saturate the present bound from GERDA and KamLAND-Zen experiments. Also, we briefly explain how keV-MeV range RH neutrino arising from our model can saturate various astrophysical and cosmological constraints and can be considered as warm Dark Matter (DM) candidate to address various cosmological issues. We also discuss on left-right theories with Higgs doublets without having scalar bidoublet leading to fermion masses and mixings by inclusion of vector like fermions.
Speaker: Chayan Majumdar (Indian Institute of Technology Bombay) -
184
A comparative study of 0νββ decay in symmetric and asymmetric left-right model
We study the new physics contributions to neutrinoless double beta decay ($0\nu\beta\beta$) in a TeV scale left-right model with spontaneous D-parity breaking mechanism where the values of the $SU(2)_L$ and $SU(2)_R$ gauge couplings, $g_L$ and $g_R$ are unequal. Neutrino mass is generated in the model via gauge extended inverse seesaw mechanism. We embed the model in a non-supersymmetric $SO(10)$ GUT with a purpose of quantifying the results due to the condition $g_{L} \neq g_{R}$. We compare the predicted numerical values of half life of $0\nu\beta\beta$ decay, effective Majorana mass parameter and other lepton number violating parameters for three different cases; (i) for manifest left-right symmetric model ($g_L = g_R$), (ii) for left-right model with spontaneous D parity breaking ($g_L \neq g_R$), (iii) for Pati-Salam symmetry with D parity breaking ($g_L \neq g_R$). We show how different contributions to $0\nu\beta\beta$ decay are suppressed or enhanced depending upon the values of the ratio $\frac{g_R}{g_L}$ that are predicted from successful gauge coupling unification.
Speaker: Supriya Senapati (Indian Institute of Technology, Bombay) -
185
Electromagnetic neutrino interactions in elastic neutrino-proton scattering
We develop a basic theoretical apparatus for the search of electromagnetic neutrino interactions in experiments on elastic neutrino-nucleus scattering [1]. Using our approach developed for the case of elastic neutrino-electron collisions in [2], we take into account all electromagnetic form factors of massive neutrinos [3] in the present treatment. In this contribution we focus on elastic neutrino-proton scattering, which can be important for studying supernova neutrinos in experiments, for example, such as JUNO [4]. In our consideration we take into account all electromagnetic form factors not only of a neutrino, but of a proton as well.
[1] M. Cadeddu, C. Giunti, K. A. Kouzakov, Y. F. Li, A. I. Studenikin, and Y. Y. Zhang, Phys. Rev. D 98, 113010 (2018), arXiv:1810.05606.
[2] K. A. Kouzakov and A. I. Studenikin, Phys. Rev. D 96, 099904 (2017), arXiv:1703.00401.
[3] C. Giunti and A. Studenikin, Rev. Mod. Phys. 87, 531 (2015), arXiv:1403.6344. [4] F. An et al, J. Phys. G 43.3, 030401 (2016), arXiv:1507.05613.Speaker: Fedor Lazarev (MSU) -
186
Phenomenological study of keV scale sterile neutrino dark matter with $S_4$ flavor symmetry
Searching for the cosmological origin, constituents and the interactions of dark matter
has been a great challenge to the fundamental science today. With the motivation of connecting dark matter phenomenology with neutrino, we have chosen inverse seesaw ISS (2,3) framework which is the extension of the standard model by the addition of two right handed neutrinos and three sterile fermions. The significance of the model is that it leads to a light sterile state with the mass in the keV range along with three light active neutrino states. The lightest sterile neutrino in keV scale can account for a feasible dark matter(DM) candidate. To strengthen our dark matter model, $S_{4}$ flavor symmetry has been incorporated which is further augmented by $Z_{4}\times Z_{3}$
symmetry to constrain the Yukawa Lagrangian. We have performed detailed numerical
analysis including the calculation of DM mass and mixing with the active
neutrinos, decay rates of possible interaction as well as the relic abundance which are the key factors for considering sterile neutrino as a viable dark matter candidate. We constrain the parameter space of our model with the latest astrophysical and cosmological data.Speaker: Ms Nayana Gautam (Tezpur University,Assam) -
187
Neutrino spin-flavour and collective oscillations in supernovae
We present an analysis of a neutrino flux evolution in an extreme astrophysical environment peculiar to supernovae accounting for effects of an arbitrarily moving media and a strong magnetic field. For neutrinos propagating inside a supernova the resonances in the flavour and spin-flavour oscillations engendered by the neutrino magnetic moment interaction with a magnetic field and weak interactions with the transversally moving matter are accounted for [1,2]. In addition, we also account for the effect of the collective neutrino oscillations and discuss possible spectral splits of the final neutrino fluxes that can arise due to spin and spin-flavour oscillations in this case.
[1] A. Studenikin, Neutrinos in electromagnetic fields and moving media, Phys.Atom.Nucl. 67 (2004) 993-1002 (Yad.Fiz. 67 (2004) 1014-1024).
[2] P. Pustoshny, A. Studenikin, Neutrino spin and spin-flavour oscillations in transversal matter currents with standard and non-standard interactions, Phys. Rev. D 98 (2018) 113009.
Speaker: Yufeng Li (Institute of High Energy Physics, Chinese Academy of Sciences) -
188
Neutrino oscillations in a magnetic field: the three-flavor case
We develop the approach to the problem of neutrino oscillations in a magnetic field introduced in [1] and extend it to the case of three neutrino generations. The theoretical framework suitable for computation of the Dirac neutrino spin, flavour and spin-flavour oscillations probabilities in a magnetic field is given. The closed analytic expressions for the probabilities of oscillations are obtained accounting for the normal and inverted hierarchies and the possible effect of CP violation. In particular, it is shown that the probabilities of the conversions without neutrino flavor change, i.e. $\nu_e^L \rightarrow \nu_e^L$ and $\nu_e^L \rightarrow \nu_e^R$, do not exhibit the dependence on the CP phase, while the other neutrino conversions are affected by the CP phase. In general, the neutrino oscillation probabilities exhibit quite a complicated interplay of oscillations on the magnetic $\mu_{\nu} B$ and vacuum frequencies. The obtained results are of interest in applications to neutrino oscillations under the influence of extreme astrophysical environments, for example peculiar to magnetars and supernovas, as well as in studying neutrino propagation in interstellar magnetic fields (see [2]).
Speaker: Alexey Lichkunov (Lomonosov Moscow State University) -
189
Astrophysical neutrino oscillation accounting for neutrino charge radii
It is believed that the running (for instance, COHERENT) and forthcoming terrestrial neutrino experiments will be sensitive to the neutrino charge radius [1] that is one of the neutrino fundamental electromagnetic characteristics [2] predicted [3] to be non-zero even in the Standard Model. In this work we derive the neutrino evolution equation accounting for charge radii for the case of the neutrino propagation in an extreme astrophysical environment. On this basis, we study conditions for new neutrino oscillation resonances in astrophysical environments (such as supernovae, neutron and binary neutron stars) accounting for neutrino magnetic moments and charge radii. We discuss possibilities to have reasonable effects of the charge radii on supernovae neutrino fluxes in the forthcoming large volume neutrino experiments.
[1] M. Cadeddu, F. Dordei, C. Giunti, K. Kouzakov, E. Picciau, A. Studenikin, Phys. Rev. D100 (2019) 073014.
[2] C. Giunti, A. Studenikin, Rev.Mod.Phys. 87 (2015) 531.
[3] J. Bernabeu, L. G. Cabral-Rosetti, J. Papavassiliou, and J. Vidal, Phys. Rev. D62 (2000) 113012.
Speaker: Konstantin Stankevich (Lomonosov Moscow State University) -
190
Baryogenesis, thermal and non-thermal production of dark matter within the IHDM desert in Scotogenic model
The Scotogenic model is a minimal extension of Standard Model by three neutral singlet fermions($N_{k}$) and an inert scalar doublet($\eta$) which are $Z_{2}$ odd.Considering this model,we choose the lightest neutral scalar($\eta_{0}$) as the DM candidate with its mass lying in the intermediate mass range,i.e $M_{W}$ < $M_{DM}$ $\leq $550 GeV to show relic abundance and the lightest of $N_{k}$ with $M_{N_{1}}$ as low as 10 TeV to show $N_{1}$ baryogenesis.The calculation of baryogenesis is carried out with the lightest neutrino mass obeying the recent Planck limit and the effective neutrino mass satisfying the bounds from KamLAND-Zen.The mass splitting of the other scalars in $\eta$ field is varied to see how it affects the thermal as well as non thermal production of observed relic.We also scan the parameter space for DM-Higgs coupling $\lambda_{L}$ and $M_{DM}$,taking into account bounds from relic abundance and direct detection experiment XENON1T.
Speaker: Ms Lavina Sarma (Tezpur University)
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182
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Beyond the Standard Model - Posters: Block IConvener: Iurii Karpenko (Czech Technical University in Prague)
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191
Search for high mass resonance in di-jet and di-b-jet events using 139 fb−1 of pp collisions at √s=13 TeV with the ATLAS detector
New resonances decaying into pairs of quarks or gluons appear in a variety of new physics models from simple gauge extensions of the standard model to Grand Unified Theories. The dijet final state at high transverse momentum can probe the highest energies reached in a collider experiment. This corresponds to the largest reach in mass for the production of new particles. Some BSM particles may preferentially decay into bb or bj, so besides of the search in generic di-jets, we also considered the case in which one or two jets identified as b-jets. This poster will show the latest results of search for new resonance in di-jet and di-b-jet events using the full Run 2 pp collision dataset at √s = 13 TeV, corresponding to an integrated luminosity of 139 fb-1 collected from 2015 to 2018 with the ATLAS detector.
Speaker: Dengfeng Zhang (Tsinghua University (CN)) -
192
Search for Scalar Leptoquark Pair Production Decaying into Top-Quarks and Leptons at √s = 13 TeV with ATLAS detector
This poster presents a search for pair-produced scalar leptoquarks decaying to leptons and hadronic top quarks using 139 fb-1 of data recorded by the ATLAS detector at √s = 13 TeV. As well as being predicted by various extensions of the Standard Model to describe the similarity between the quark and lepton sectors, leptoquarks provide a promising explanation for anomalies observed in both the lepton universality tests in B decays and muon anomalous magnetic moment measurement. Searches for pair-produced scalar leptoquarks decaying to electron-top or muon-top pairs have been performed in final states with exactly two leptons. A parameterized gradient boosted decision trees approach is used to suppress the standard model background. Improved exclusion limits are set on the leptoquark masses are set at 95% confidence level.
Speaker: Vincent Wai Sum Wong (University of British Columbia (CA)) -
193
Search for excited leptons in CMS
Compositeness models are a popular explanation for the observed three generations of standard model (SM) particles. One consequence of compositeness would be the observation of excited leptons, such as excited electrons, e, or excited muons, mu. At the LHC such particles could be produced in pp collisions under the assumption that leptons are composite objects. Produced excited leptons are expected to transition to their corresponding SM lepton partner via gauge or via contact interaction. CMS has performed a recent search for e and mu in the contact interaction decay channel leading to a two-lepton plus two-jets final state using the 2016 and 2017 $\sqrt{s} = 13$ TeV dataset. While no signal was observed, the exclusion results provide the best limits to date.The poster also compares to other complementary search channels and discusses the greater context of excited leptons searches.
Speaker: Kerstin Hoepfner (Rheinisch Westfaelische Tech. Hoch. (DE)) -
194
Observation of light-by-light scattering and search for axion-like particles with the CMS experiment
Ultraperipheral lead-lead collisions at $\sqrt{s_{NN}} = 5.02$ TeV produce such very large photon fluxes that the fundamental, and very rare, quantum-mechanical process of Light-by-light (LbyL) scattering can be observed. The studies of LbyL scattering in ultraperipheral PbPb collisions data collected during the 2015 and 2018 LHC runs will be presented, using samples corresponding to integrated luminosities of about $0.4\,\textrm{nb}^{-1}$ and $1.6\,\textrm{nb}^{-1}$, respectively. The cross section for this process is sensitive to the possible existence of axion-like particles. The four times more luminosity with 2018 PbPb collisions provides an access to axion mass and coupling ranges that are inaccessible with pp data, opening a unique window through which to search for physics beyond the Standard Model.
Speaker: Rebeka Lilla Böttger (MTA-ELTE & BME) -
195
Model Unspecific Search in CMS (MUSiC)
The Model Unspecific Search in CMS (MUSiC) analysis searches for anomalies in data that can be probed for new physics phenomena based purely on the comparison of the recorded data to the expectation according to the standard model (SM), obtained from simulations. Events selected with at least one lepton are classified into several hundred event classes based on their final state topology, taking electrons, muons, photons, jets, b-tagged jets, and missing transverse momentum into account, and an automated search algorithm subsequently surveys kinematic distributions of the data for deviations from the SM expectation without any explicit input of any particular new physics models. The search strategy and the results of the MUSiC analysis using 35.9fb−1 of data recorded by the CMS detector at the CERN LHC during proton-proton collisions at a center of mass energy of 13 TeV will the presented.
Speaker: Lorenzo Vigilante (Rheinisch Westfaelische Tech. Hoch. (DE)) -
196
CP-violating Wtb anomalous couplings through top-pair production via pp collision at LHC.
We discuss the CP-violating effects at partonic level arising due to anomalous Wtb vertices at the Large Hadron Collider in the semileptonic decay modes of the top-quark for the ttbar events at the LHC. Limits on these anomalous couplings are also discussed for the 13 TeV LHC energy run. The improvements over these estimates for the forthcoming HL-LHC with 14 and 27 TeV and FCC-hh with 100 TeV centre-of-mass energies are also presented.
Speaker: Ms Apurba Tiwari (Aligarh Muslim University)
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191
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Top Quark and Electroweak Physics - Posters: Block IConvener: Kamil Augsten (Czech Technical University (CZ))
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197
Measurements of inclusive four-lepton production at ATLAS
Measurements of the four-lepton invariant mass spectrum are made with the ATLAS detector, using proton-proton collisions at √s=13 TeV delivered by the Large Hadron Collider. The measurement is done selecting events that contain two same-flavour opposite-sign lepton pairs. The four-lepton mass exhibits a rich structure, with different mass regions dominated by single Z production, Higgs production and on-shell ZZ production, with a complex mix of interference terms and possible contributions from beyond-the-Standard model (BSM) physics. The measurement is corrected for detector effects and compared to state-of-the-art Standard Model calculations, which are found to be consistent with the data. Constraints on example BSM scenarios are evaluated, and further re-interpretations can be made with the provided information.
Speaker: Xiaotian Liu (University of Science and Technology of China (CN)) -
198
Top-quark-antiquark production in association with a photon in the electron-muon channel at a centre-of-mass energy of 13 TeV with the ATLAS detector
The cross-section of top-quark-antiquark pair production in association with a photon is important in order to determine the electromagnetic coupling of the top-quark with high precision. It is also of great significance to test deviations from the Standard Model (SM), such as anomalous dipole moments of the top-quark. Furthermore, such cross-section can be interpreted in effective field theories which would allow for probing effects of higher-dimensional operators of the SM fields.
The presentation covers the inclusive and differential cross-section measurements of top-quark production in association with a photon in the electron-muon channel at $\sqrt{s}=$13 TeV with the ATLAS detector.
Both measurements are performed in a fiducial volume. The inclusive cross-section is extracted using a profile likelihood fit, while the differential cross-section is measured at parton level as a function of various observables, such as the photon transverse momentum and angular variables related to the photon and the leptons. The measurements are compared to the most recent next-to-leading order theory calculation [JHEP 10 (2018) 158] and state-of-the-art Monte Carlo simulations. The results are found to be in good agreement with the predictions within uncertainties.Speaker: John Kamal Rizk Meshreki -
199
WZ production in leptonic decays at CMS
The study of the associated production of W and Z bosons is performed in proton-proton collisions using data collected by the CMS experiment. WZ production is one of the dominant multiboson production processes at the LHC energies. Thus, a good understanding of this process improves our understanding of the Standard Model. Inclusive cross section measurements and differential cross section measurements for different variables are provided. Anomalous couplings and boson polarization are also presented
Speaker: Bárbara Álvarez González (Universidad de Oviedo (ES)) -
200
Probing the prospective FCC-he sensitivities on the electromagnetic dipole moments of the top-quark
The measurement of the top-quark anomalous electromagnetic couplings is one of the most
important goals of the top-quark physics program in the present and future collider experiments.
This would provide direct information on the non-standard interactions of the top-quark. We study
a top-quark pair production scenario at the Future Circular Hadron-Electron Collider (FCC-he)
through $e^-p \to e^-\gamma p \to \bar t \nu_e b p$ collisions, which will provide information about sensitivities on
anomalous $\hat{a}_V$ and $\hat{a}_A$ couplings at a 95% C.L., and the possibility of probing new physics.Speaker: Dr Maria A. Hernandez-Ruiz (Universidad Autónoma de Zacatecas)
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197
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Quark and Lepton Flavour Physics - Posters: Block IConvener: Martin Spousta (Charles University)
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201
Statistical combination of searches for the X(5568) state decaying into $B^0_s π ^±$
A statistical combination of the search results for the X(5568) resonance decaying into $𝐵^0_𝑠 π^{±}$ is reported, based on published results from the ATLAS, CMS, CDF and LHCb Collaborations.
A narrow structure in the invariant mass distribution of $𝐵^0_𝑠 π^{±}$ has been observed by the D0 Collaboration with a mass value of 5568 MeV and interpreted as the first observation of a possible tetra-quark state with four different flavours. The evidence of such a state was not confirmed by any of the latest searches from LHCb, CDF, ATLAS and CMS Collaborations.
CDF and the LHC experiments have set limits on $\rho_𝑋$, the relative production rate of the X(5568) and $𝐵^0_𝑠$ states times the branching ratio for the $𝑋(5568)\rightarrow 𝐵^0_𝑠 π^{±}$ decay.
With a statistical combination of limits set by the three LHC experiments, we derive a limit, at 95% Confidence Level, of $\rho_𝑋$ < 0.92% for $𝑝_𝑇(𝐵^0_𝑠)$ > 10 GeV, and $\rho_𝑋$ < 0.91% for $𝑝_𝑇(𝐵^0_𝑠)$ > 15 GeV, which represent the most stringent upper limits up to present.
The talk will review the experimental results from Tevatron and LHC, will describe the combination procedure and the obtained results. The effect of including the results from Tevatron experiments in the statistical combination will also be discussed.Speaker: Paolo Iengo (CERN) -
202
The study of the rare decays $B^{0}_s \rightarrow \mu^+\mu^-$ at $\sqrt{s}$ = 13 TeV with the ATLAS detector
The flavour-changing neutral currents of the rare decays $B^{0}_s \rightarrow \mu^+\mu^-$ provide a favourable environment to observe new physics. The study of these decays, using the data collected by the ATLAS detector, is presented. Their branching ratios are measured relative to the reference decay mode $B^{+/-} \rightarrow J/\psi K^{+/-}$, which is abundant and has a well-measured branching fraction B($B^{+/-} \rightarrow J/\psi K^{+/-}$) $\times$ B($J/\psi \rightarrow \mu^+\mu^-$). The event yields of the reference and the rare-decay channels are extracted employing the unbinned maximum likelihood fit approach.
Speaker: Mazuza Ghneimat (Universitaet Siegen (DE)) -
203
Measurement of CP Violation in the B0s to J/psi(mu+mu-)phi(K+K-) decay with 2017 and 2018 data in CMS
Analysis details concerning the new CMS measurement of CP Violation in
B0s to J/psi phi decay with 2017 and 2018 13TeV data will be presented.Speaker: Muhammad Alibordi (Indian Institute of Technology Madras (IN)) -
204
Discriminating new physics scenarios in $b\rightarrow s\,\mu^+\,\mu^-$ via transverse polarization asymmetry of $K^*$ in $B\rightarrow K^*\,\mu^+\,\mu^-$ decay
A global fit to current $b\rightarrow s\,l^+\,l^-$ data suggest several new physics solutions. Considering only one operator at a time and new physics in the muon sector, it has been shown that the new physics scenarios (I) $C_9^{\rm NP}<0$, (II) $C_{9}^{\rm NP} = -C_{10}^{\rm NP}$, (III) $C_9^{\rm NP} = -C_9^{\rm 'NP}$ can account for all data in this sector. In order to discriminate between these scenarios one needs to have a handle on additional observables in $b \to s \, \mu^+ \, \mu^-$ sector. In this work we study transverse polarization
asymmetry of $K^*$ polarization in $B\rightarrow K^*\,\mu^+\,\mu^-$ decay, $A_T$, to explore such a possibility. We show that $A_T$ is a good discriminant of all the three scenarios. The measurement of this asymmetry with a percent accuracy can confirm which new physics scenario is the true solution, at better than 3$\sigma$ C.L.Speaker: Suman Kumbhakar (IIT Bombay) -
205
Improved determination of |Vus| with tau decays
We present improved determinations of |Vus| with tau decays relying on the HFLAV tau branching fractions global fit results. Precision improvements come from using recent resuts from BaBar and recent evaluations with lattice of the electromagnetic (e.m.) and strong isospin-breaking corrections to the π+→μ+ν[γ] and K+→μ+ν[γ] leptonic decay rates. A third determination of |Vus| has been added to the two ones that are included in the HFLAV 2017 report. The last HFLAV report is available as a preprint and is being submitted for publication at the beginniog of 2020.
Speaker: Alberto Lusiani (Scuola Normale Superiore and INFN, sezione di Pisa) -
206
Untagged analysis of B → πlν̄ and first measurement of |Vub| at Belle II
A long standing discrepancy between the results of exclusive and inclusive measurements of the CKM matrix element |Vub| exists. The charmless semileptonic decay B → πlν̄ is one of the most accessible and powerful channels for determining |Vub| in exclusive modes at e+ e− B-factories. Using data from the Belle II experiment, a new precision measurement of |Vub| becomes possible. In preparation for first precision measurements, an untagged measurement method for extracting B → πlν̄ events is developed. Lepton and pion candidates are combined to form B → πlν̄ candidates. In order to increase the purity, a series of selections is imposed to suppress continuum and other backgrounds. Signal is extracted from a fit to the two-dimensional ∆E and Mbc distribution in bins of the momentum transfer squared of the B-meson to the pion final state. A simultaneous form factor fit to the measured partial branching fractions and lattice QCD input is carried out to determine values of |Vub|.
Speaker: Svenja Granderath (Rheinische Friedrich-Wilhelms-Universität Bonn)
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201
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Astro-particle Physics and Cosmology - Posters: Block IConvener: Alexey Yushkov (Institute of Physics AS CR, Prague)
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207
Daily Cosmic-Ray Electron Fluxes by the Alpha Magnetic Spectrometer on the ISS
High-statistics, precision measurements by AMS of the daily cosmic-ray electron fluxes from May 2011 to December 2018 are presented. Detailed comparison of these fluxes with the daily fluxes of other cosmic rays measured by AMS results in several new and surprising observations.
Speaker: Weiwei Xu (Shandong University (CN)) -
208
Tachyon Logamediate Inflation on DGP Braneworld Gravity
Inflation as the intersection of cosmology and high energy physics will be studied in this manuscript. Among many inflationary models we consider the one with a logarithmic scale factor, called logamediate inflation. On the other hand, the idea of extra dimensions in cosmology is closely related to high energy physics and here, we are interested in studying the logamediate inflationary paradigm in the context of a special extra dimensional theory proposed by Dvali,Gabadadze and Porrati (DGP), in which our 4D universe is assumed to be a brane embedded in a 5D infinite Minkowski bulk. To drive inflation we use a tachyon scalar field as the inflaton field. After the reconstruction of the tachyonic potential and calculating the slow-roll parameters, we turn to perturbation theory and constrain our model parameters using new observational data. then we will show this model can be compatible with the latest observational data.
Speaker: Dr Arvin Ravanpak (Vali-e-Asr university of Rafsanjan) -
209
Density Dependent B-parameter model of Compact object with Strange Quark Matter
A class of relativistic solutions for compact cold objects with strange quark matter in a pseudo-spheroidal space-time is presented here. Considering strange matter equation of state namely, $p = \frac{1}{3}(\rho-4B)$, where $\rho$, $p$ and $B$ are energy density, pressure and MIT Bag parameter respectively, stellar models are obtained. Stellar models are explored where the Bag parameter varies with the energy density ($\rho$) inside the compact object in presence of anisotropy with a pseudo-spheroidal geometry described by Vaidya-Tikekar metric. The density dependence of $B$ for different anisotropy including isotropic case is determined here. It is noted that although $B$ varies with anisotropy inside the star, finally at the surface it attains a value which is independent of the anisotropy. The Bag parameter $B$ is found to increase with an increase in anisotropy for a given compactness factor $(M/b)$ and spheroidicity parameter ($\lambda$). It is also noted that for a star with given mass (M) and radius (b), the parameter $B$ increases with the increase of $\lambda$ and finally at large value of $\lambda$ it attains a constant value. We note that in this model equation of state (EoS) obtained from geometrical consideration with allowable value of ‘B’ is similar to that obtained by earlier investigators from consideration of microphysics. The stability of the stellar models for compact objects with anisotropy in hydro-static equilibrium is also studied.
Speaker: Dr Pradip Kumar Pradip Kumar Chattopadhyay (Coochbehar Panchanan Barma University) -
210
Detector Simulation and Reconstruction of Supernova Neutrinos with JUNO
Since the detection of neutrinos emitted by the supernova SN 1987A, no neutrinos from other supernovae have been observed to date.
The Jiangmen Underground Neutrino Observatory (JUNO) will be capable of measuring the neutrino burst from a galactic supernova explosion. High statistics, a low detection threshold and an excellent energy resolution will strongly constrain the details of the neutrino-driven supernova mechanism.
JUNO will be sensitive to signals from all neutrino flavors via different detection channels.
These are the inverse beta decay, elastic scattering on protons and electrons and various interactions with carbon. The capability of separating these channels is challenging but crucial for flavor dependent analyses of the supernova burst. We present initial results of an event classification that is based on a full detector simulation.Speaker: Thilo Birkenfeld (RWTH Aachen University) -
211
Search for Neutrino Events Associated with Gravitational Wave at Daya Bay
Several gravitational-wave (GW) events have been observed by the Advanced LIGO and Virgo detectors. Providing a connection between neutrino emission and GW bursts is obviously important for understanding the underlying physical processes associated with GW creation. The Daya Bay Reactor Neutrino Experiment is designed for measuring the neutrino mixing angle theta13 using reactor antineutrinos at the Daya Bay Power Plant in South China. It has 8 antineutrino detectors with identical design positioned at multiple baselines that help in suppressing incoherent cosmogenic backgrounds and detector-related noises. During the years since the discovery of the first GW signal, Daya Bay has been running continuously and smoothly. In this poster, we will present the latest results of a search for electron anti-neutrino signals in coincidence with the detected GW events.
Speaker: Prof. Wei Wang (Sun Yat-Sen University) -
212
Constraints on the origin of the UHECR dipole anisotropy outside the Galaxy
The dipole anisotropy of ultra-high energy cosmic rays above 8 EeV detected by the Pierre Auger Observatory indicates an extragalactic origin of these particles. However, both the direction and the amplitude of the dipole of cosmic rays outside our Galaxy might be different than the one observed on Earth due to the effects of the Galactic magnetic field. We present an analysis of effects of the Galactic magnetic field on arrival directions of cosmic rays using numerical simulations within the CRpropa3 package. Jansson-Farrar model of the Galactic magnetic field is used to propagate particles inside the Galaxy. We investigate possible directions and amplitudes of the dipole outside the Galaxy for different mass composition scenarios so that the final direction and amplitude on Earth is compatible with the measured dipole.
Speaker: Alena Bakalova
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207
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Accelerator: Physics, Performance, and R&D for Future Facilities - Posters: Block IConvener: Tomas Sykora (Charles University (CZ))
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213
Muon Ionization Cooling Demonstration by Normalized Transverse Emittance Reduction in MICE 'Flip Mode'
Low emittance muon beams are central to the development of facilities such as a Neutrino Factory or a Muon Collider. The international Muon Ionization Cooling Experiment (MICE) was designed to demonstrate and study the cooling of muon beams. Several million individual muon tracks have been recorded passing through a liquid hydrogen or a lithium hydride absorber. Beam sampling routines were employed to account for imperfections in beam matching at the entrance into the cooling channel and enable an improvement of the cooling performance. A study of the change in normalized transverse emittance in a flipped polarity magnetic field configuration is presented and the characteristics of the cooling effect are discussed.
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Speaker: Mr Paul Jurj (Imperial College London) -
214
Emittance exchange in MICE
Highly brilliant muon beams for a muon collider can be made from the bombardment of protons against a target producing pions, which subsequently decay into muons. Such a muon beam occupies a large phase-space volume and must be cooled to achieve luminosities suitable for a muon collider. The Muon Ionization Cooling Experiment (MICE) has demonstrated transverse ionization cooling. A muon collider requires both longitudinal and transverse cooling. This can be achieved through a wedge-shaped absorber, where both the longitudinal and transverse phase spaces are simultaneously manipulated during the ionization cooling process. The change in longitudinal and transverse phase space densities obtained from placing a polyethylene wedge into the MICE cooling channel are presented here.
Speaker: craig brown -
215
Transverse Emittance Change in MICE 'Solenoid Mode' with Muon Ionization Cooling
Emittance reduction of muon beams is an important requirement in the design of a next-generation Neutrino Factory or Muon Collider. Ionization cooling has been proposed to meet this requirement, whereby beam emittance is reduced by passing a beam through absorbing material. Tight focussing is required in both horizontal planes, which is achieved in many designs using solenoid focussing. Ionization cooling has been demonstrated in the Muon Ionization Cooling Experiment (MICE) in 'flip' mode, where the solenoid field flips polarity across the absorber. We present the performance of MICE in 'solenoid' mode, where the field polarity does not change across the absorber.
Speaker: Mr Tom Lord (University of Warwick) -
216
Muon Trigger using Deep Neural Networks accelerated by FPGAs
Accuracy and latency are crucial to the trigger system in high luminosity particle physics experiments. We investigate the usage of deep neural networks (DNN) to improve the accuracy of the muon track segment reconstruction process at the trigger level. Track segments, made by hits within a detector module, are the initial partial reconstructed objects which are the typical building blocks for muon triggers. Currently, these segments are coarsely reconstructed on FPGAs to keep the latency manageable. DNNs are ideal for these types of pattern recognition problems, and so we examine the potential for DNN based track segment reconstruction to be accelerated by dedicated FPGAs to improve both processing speed and latency for the trigger system.
Speakers: Jason Lee (University of Seoul (KR)), Youngwan Son (University of Seoul), Ian James Watson (University of Seoul) -
217
Integrated luminosity measurement at CEPC
The very forward region of a detector at future e+e- collider is the one of the most challenging regions to instrument. A luminometer – compact calorimeter dedicated for precision measurement of the integrated luminosity at a permille level or better is needed. Here we review a feasibility of such precision at CEPC, considering detector mechanical precision and beam-related requirements. We also discuss capabilities of experimental determination of the beam-energy spread, from the perspective of integrated luminosity precision requirements at the Z0 pole.
Speaker: Ivan Smiljanic (Vinca Institute of Nuclear Sciences, University of Belgrade (RS)) -
218
HEP Graph Analysis to Protect Children from Violence
Data Analysis Methods from High Energy Particle Physics (HEP) have applications well beyond fundamental research or the obvious industrial use cases. We would like to present the results of two project together with the UNICEF hosted End Violence Against Children (EVAC) Global Partnership and the Terre des Hommes (TdH) Innovation Prize project ChildHub. We used HEP data analysis inspired techniques to analysis Millions of financial transactions of the United Nations in order to identify collaborations between different countries, institutions and thematic direction, as well as interconnections of data in document libraries and communities of Child Protection practitioners. Besides the presentation of the results we will discuss how data analysis techniques from fundamental HEP research can help to demonstrate the value and impact on society in often not obvious domains (like Ending Violence Against Children) and how they can be used for outreach towards fundamental science funding decision makers.
Speaker: Dr Andrea Martini (gluoNNet Association) -
219
How HEP contributes to Sustainable Investment?
The Sustainable Development Goals (SDGs) of the United Nations as well as the Environmental, Social and corporate Governance (ESGs) are central factors in measuring the sustainability and societal impact of an action or an investment. Following research on sustainable investment with the Global Humanitarian Lab (GHL) we are analysing partnerships and collaborations between United Nations system organisations as well as private sector entities. The mapping and correlation techniques use models originally developed for HEP particle tracking and interconnected data graph/network analysis including Graph Neural Networks (GNN). We will present initial results of a mapping excursive in collaboration with Impact17 and the United Nations SDG Lab as well as discuss how HEP inspired analysis techniques can contribute to smart decision taking in sustainable investment and policy making, and through that showcase how fundamental research can contribute to create value for non-HEP domains.
Speaker: Steve Hamm (CIVIC) -
220
High energy plasma in vacuum system generated by microwave surfatron generator surfatron resonator i
With the continued down scaling of devices and structure changed to 3-dimensional, new engineering processes are in great demand. Microwave surfatron plasma is considered new plasma source because it enables very low-temperature deposition and good quality due to its low electron temperature and higher plasma density. For adopting surfatron plasma source to new vacuum chamber, it is essential to understand the physical properties of generated plasma with the varying gas atmosphere. Also we are requested to achieve acceptable homogeneity on large area. Thus, in this work, we investigated plasma parameters with various gas, pressure, flow and various distances from the plasma outlet with optimized design of plasma nozzle.
Speaker: Dr jihye kim
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213
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Operation, Performance and Upgrade of Present Detectors - Posters: Block IConveners: Jiri Kroll (Czech Academy of Sciences (CZ)), Jakub Kandra (Charles University)
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221
Calibration and Performance of the CMS Electromagnetic Calorimeter in LHC Run2
Many physics analyses using the Compact Muon Solenoid (CMS) detector at the LHC require accurate, high resolution electron and photon energy measurements. Excellent energy resolution is crucial for studies of Higgs boson decays with electromagnetic particles in the final state, as well as searches for very high mass resonances decaying to energetic photons or electrons. The CMS electromagnetic calorimeter (ECAL) is a fundamental instrument for these analyses and its energy resolution is crucial for the Higgs boson mass measurement. Recently the energy response of the calorimeter has been precisely calibrated exploiting the full Run 2 data, aiming at a legacy reprocessing of the data. A dedicated calibration of each detector channel has been performed with physics events exploiting electrons from W and Z boson decays, photons from pi0/eta decays, and from the azimuthally symmetric energy distribution of minimum bias events. The calibration strategies that have been implemented and the excellent performance achieved by the CMS ECAL with the ultimate calibration of Run 2 data, in terms of energy scale stability and energy resolution, are presented.
Speaker: Dmitri Konstantinov (State Res. Center of Russian Fed. - Inst. for High Energy Phys., Russian Federation) -
222
Collection of web tools for ATLAS Tile Calorimeter data quality tasks
The ATLAS Tile Calorimeter (TileCal), as a substantial part of the hadronic calorimeter system of the ATLAS detector, records energy deposits and jointly with other calorimeters reconstructs hadrons, jets, tau-particles and missing transverse energy. It also assists in muon identification. The TileCal is the hadronic sampling calorimeter, which is constructed out of alternating iron absorber layers and active scintillating tiles and covers region |eta| < 1.7. Its operation is closely monitored by several systems, which were independently developed to meet distinct collaboration requirements. Any problem or indication of a problem is reported and immediately investigated, which resulted in data quality (DQ) efficiency close to 100% in the last several years. Although the TileCal tools are maintained and still being developed, the underlying technologies on which they were developed, especially web related
tools, are becoming gradually outdated.The goal of the Tile-in-One (TiO) web platform is to integrate all the different TileCal DQ tools, independently developed over long period of time by different groups and individuals into one cohesive system without any non-necessary overlap in functionality. It is implemented as a collection of relatively small independent web applications designed for one specific task, which are accessed through the main TiO server, which handles the authentication. Every application is isolated in its own virtual machine and is called plugin. Currently, the platform operates with around 13 plugins in various stages of development and focuses not only on reimplementation of the old tools but also creation of new ones. The implementation details of the Tile-in-One web platform and also a selection of plugins will be presented.
Speaker: Juraj Smiesko (Slovak Academy of Sciences (SK)) -
223
ATLAS Tile Calorimeter time calibration, monitoring and performance in Run 2
The Tile Calorimeter (TileCal) is the central section of hadronic calorimeter of the ATLAS experiment at the LHC. This sampling device uses steel plates as absorber and scintillating tiles as active medium and its response is calibrated to electromagnetic scale by means of several dedicated calibration systems.
The accurate time calibration is important for the energy reconstruction, non-collision background removal as well as for specific physics analyses. The initial time calibration using so-called splash events and subsequent fine-tuning with collision data are presented. The monitoring of the time calibration with laser system and physics collision data is discussed as well as the corrections for sudden changes performed still before the recorded data are processed for physics analyses. Finally, the time resolution as measured with jets in Run 2 is presented.Speaker: Michaela Mlynarikova (Charles University (CZ)) -
224
Abstract for The JUNO Calibration Strategy and its Simulation
Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector under construction in China,which is designed to primarily determine the neutrino Mass Hierarchy(MH) by detecting reactor anti-neutrinos via inverse beta decay.JUNO energy response is strongly position-dependant due to the detector structure and dimension.The energy resolution should be <3%/ (the quantity under the square root sign is E) to determine MH in 3σ in 6 years, so the calibration complex is very critical and has been designed.In this poster, the study including Calibration Strategy and simulation work will be presented.
Speaker: Mr Kangfu Zhu (xi'an jiaotong university) -
225
Measurements of Luminosity in ATLAS with Tile Calorimeter
Luminosity measurements in ATLAS are provided primarily by LUCID detector, but rely on other detectors for determining the systematics associated with this measurement. The Tile Calorimeter, the central hadronic calorimeter at the ATLAS experiment, plays an especially important role because the Tile luminosity measurement is independent of pileup, a feature shared with the Track counting luminosity measurement. Comparison of the LUCID luminosity measurements in different run conditions to those obtained by Tile and Tracking, as well as a comparison of Tile to Tracking, is used to measure and study the dominate systematic uncertainty associated with the LUCID Luminosity measurement. Here the methods of measuring ATLAS luminosity with the Tile Calorimeter and its transformation to a systematic uncertainty are described.
Speaker: Sergio Gonzalez Fernandez (The Barcelona Institute of Science and Technology (BIST) (ES)) -
226
Measuring luminosity with track counting in the ATLAS experiment
The precise measurement of the luminosity is one of the key requirements for every ATLAS analysis at the Large Hadron Collider (LHC) at CERN. Particularly in high precision experiments, the uncertainty on the luminosity can be one of the main limitations. Therefore, its reduction is the prime goal of the ATLAS luminosity program, requiring a precise understanding of the contributing factors. The two largest individual components are the calibration transfer and the long term stability, both being determined involving the track counting luminosity measurement. The track counting method uses the average number of reconstructed charged particle tracks in the ATLAS Inner Detector as measure for the instantaneous luminosity in proton-proton collisions.
In the track counting luminosity measurement, a number of effects influence the measured number of tracks. These include, for example, the number of simultaneous pp collisions, denoted as $\mathrm{\mu}$, and the filling pattern of the individual proton bunches.
The poster discusses the impact of the different components on the uncertainty of the luminosity measurement in general and the track counting luminosity measurement in particular. The primary focus is the dependence on the LHC filling pattern. A better understanding of these effects will help to reduce the uncertainty in the ATLAS luminosity measurement.Speaker: Paul Moder -
227
Luminosity Determination using Z->ll Counting for Run-2 ATLAS Data
During Run 2, LHC delivered instantaneous luminosities of $\approx 10^{34}$ cm$^{-2}$ s$^{-1}$ at $\sqrt{s}=13\; {\rm TeV}$. This permitted monitoring of the luminosity over a time granularity as short as $60\;{\rm s}$, using the counts of $Z\rightarrow \ell \ell$ events reconstructed by selecting two, well-idenfitied high $p_T$ electrons or muons in the invariant mass range of $66 < m_{\ell \ell} < 116$ GeV.
The poster illustrates the measurement principles based on time-dependent trigger and reconstruction efficiency corrections and shows the stability of using both $Z\to ee$ and $Z\to \mu \mu$ boson counting as luminometers. Emphasis is given to illustrate with selected LHC run examples the robustness of the method with respect to pile-up and the LHC bunch structure, which are of particular importance for reliable luminosity monitoring at the upcoming high luminosity phase of the LHC.
Speaker: Michael William O'Keefe (University of Liverpool (GB))
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221
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Detectors for Future Facilities (incl. HL-LHC), R&D, Novel Techniques - Posters: Block IConveners: Susanne Kuehn (CERN), Peter Kodys (Charles University (CZ))
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228
A muon tracking algorithm for Level 1 trigger in the CMS barrel muon chambers during HL-LHC
The electronics of the CMS (Compact Muon Solenoid) DT (Drift Tubes) chambers will need to be replaced for the HL-LHC (High Luminosity Large Hadron Collider) operation due to the increase of occupancy and trigger rates in the detector, which cannot be sustained by present system. A system is being designed that will forward asynchronously the totality of the chambers signals to the control room, at full resolution. A new backend system will be in charge of building the trigger primitives of each chamber out of this asynchronous information, aiming at achieving resolutions comparable to the ones that the offline High Level Trigger can obtain nowadays. In this way, the new system will provide improved functionality with respect to present system, allowing to improve the resilience to potential aging situations. An algorithm for the trigger primitive generation that will run in this new backend system has been developed and implemented in firmware. The performance of this algorithm has been validated through different methods: from a software emulation approach to hardware implementation tests. The performance obtained is very good, with optimal timing and position resolutions, close to the ultimate performance of the DT chamber system. One important validation step has included the implementation of this algorithm in a prototype chain of the HL-LHC electronics, which has been operated with real DT chambers under cosmic data taking campaigns. The new trigger primitive generation has been implemented in the so-called AB7, spare uTCA boards from present DT system which host Xilinx Virtex 7 FPGAs. The performance of this prototyping system has been verified and will be presented in this contribution, showing the goodness of the design for the expected functionality during HL-LHC.
Speaker: Jaime Leon Holgado (CIEMAT, Spain) -
229
The CMS Level-1 Endcap Muon Trigger at the High-Luminosity LHC
In the CMS endcap region, muon reconstruction in the Level-1 (L1) trigger is not straightforward because of the non-uniform magnetic field, high pile-up and punch-through interactions. However, the new muon detectors and the upgraded trigger processing capabilities proposed for the Phase-2 upgrade will allow the implementation of novel techniques that successfully address these challenges. For instance, track-finding and reconstruction of the standalone and displaced muons are carried out by a neural network-based algorithm. In addition, a proposed Global Muon Trigger system will have access to tracker tracks, muon trigger tracks and standalone muon detector hits. These objects can then be combined to improve the muon momentum resolution, reduce the muon trigger rates, and form multi-object triggers such as lepton-flavour violating tau->3mu decays. We present here preliminary studies addressing all these new capabilities.
Speaker: Daniel Guerrero (University of Florida (US)) -
230
Performing precision measurements and new physics searches at the HL-LHC with the upgraded CMS Level-1 Trigger
The High-Luminosity LHC will open an unprecedented window on the weak-scale nature of the universe, providing high-precision measurements of the standard model as well as searches for new physics beyond the standard model. Such precision measurements and searches require information-rich datasets with a statistical power that matches the high-luminosity provided by the Phase-2 upgrade of the LHC. Efficiently collecting those datasets will be a challenging task, given the harsh environment of 200 proton-proton interactions per LHC bunch crossing. For this purpose, CMS is designing an efficient data-processing hardware trigger (Level-1) that will include tracking information and high-granularity calorimeter information. The current conceptual system design is expected to take full advantage of FPGA and link technologies over the coming years, providing a high-performance, low-latency computing platform for large throughput and sophisticated data correlation across diverse sources. The envisaged L1 system will more closely replicate the full offline object reconstruction instead to perform a more sophisticated and optimized selection. Algorithms such as particle flow reconstruction can be implemented and complemented by standalone trigger object reconstruction. The expected performance and physics implications of such algorithms are studied using Monte Carlo samples with hιgh pile-up, simulating the harsh conditions of the HL-LHC. The trigger object requirements are not only driven by the need to maintain physics selection thresholds to match those of the Phase-1, the selection of exotic signatures including displaced objects must be provided to help expanding the physics reach of the experiment. The expected acceptance increase on selected benchmark signals obtained by the upgraded CMS Phase-2 Level-1 trigger will be summarized in this presentation.
Speaker: Emily Mac Donald (University of Colorado at Boulder) -
231
Triggering on electrons, photons, tau leptons, Jets and energy sums at HL-LHC with the upgraded CMS Level-1 Trigger
The High-Luminosity LHC will open an unprecedented window on the weak-scale nature of the universe, providing high-precision measurements of the Standard Model as well as searches for new physics beyond the standard model. The Compact Muon Solenoid (CMS) experiment is planning to replace entirely its trigger and data acquisition system to achieve this ambitious physics program. Efficiently collecting those datasets will be a challenging task, given the harsh environment of 200 proton-proton interactions per LHC bunch crossing. The new Level-1 trigger architecture for HL-LHC will improve performance with respect to Phase I through the addition of tracking information and subdetector upgrades leading to higher granularity and precision timing information. In this poster, we present a large panel of trigger algorithms for the upgraded Phase II trigger system, which benefit from the finer information to reconstruct optimally the physics objects. Dedicated pile-up mitigation techniques are implemented for lepton isolation, particle jets and missing transverse energy to keep the rate under control. The expected performance of the new trigger algorithms will be presented, based on simulated collision data of the HL-LHC. The selection techniques used to trigger efficiently on benchmark analyses will be presented, along with the strategies employed to guarantee efficient triggering for new resonances and other new physics signals.
Speaker: Jack Li (Northeastern University (US)) -
232
The Particle Flow Algorithm in the Phase II Upgrade of the CMS Level-1 Trigger
The CMS experiment has greatly benefited from the utilization of the particle-flow (PF) algorithm for the offline reconstruction of the data. The Phase II upgrade of the CMS detector for the High Luminosity upgrade of the LHC (HL-LHC) includes the introduction of tracking in the Level-1 trigger, thus offering the possibility of developing a simplified PF algorithm in the Level-1 trigger. We present the logic of the algorithm, along with its inputs and possible implementation. We show that this implementation is capable of operating under the limited timing and processing resources available in the Level-1 trigger environment. The expected performance and physics implications of such an algorithm are shown using Monte Carlo samples with hιgh pile-up, simulating the harsh conditions of the HL-LHC. New calorimeter features allow for better performance under high pileup (PU), provided that careful tuning and selection of the prompt clusters has been made. Additionally, advanced pile-up techniques are needed to preserve the physics performance in the high-intensity environment. We present a method that combines all information yielding PF candidates and performs Pile-Up Per Particle Identification (PUPPI) capable of running in the low latency level-1 trigger environment.
Speaker: Dylan Sheldon Rankin (Massachusetts Inst. of Technology (US)) -
233
Measurement of Liquid Scintillator Nonlinearity
Organic liquid scintillator (LS) is a common choice for detectors precisely measuring energy of electron antineutrinos. Accurate knowledge of the relation between scintillation light response and the energy deposited by a particle is essential for determination of the antineutrino energy. The response is not exactly linear. Deviation from the LS linearity is the subject of the presented investigation. The method of measurement is using Compton scattering of gammas of well known energy in the LS and precise measurement of the scattered gamma energy with HPGe detector.
Speaker: Tadeas Dohnal -
234
The Mu3e Experiment Searching for the Lepton Flavour Violating Decay μ+ → e+e+e−
The Mu3e experiment is a novel experiment to search for the lepton flavour violating (LFV) decay $\mu^{+}\rightarrow e^{+}e^{+}e^{-}$, with an ultimate sensitivity to a branching ratio of one in 2 $\times 10^{15}$ in phase I and one in $10^{16}$ muon decays for phase II, at 90 $\%$ CL. This would be an improvement in sensitivity by four orders of magnitude compared to previous searches by the SINDRUM experiment. Since this decay is suppressed to unobservable levels in the Standard Model of particle physics, any measurement of this decay would be a clear sign of new physics.
The experiment is currently under construction and will take place at the Paul Scherrer Institute in Switzerland. In order to reach this enormous number of muons, PSI is utilizing the worlds most intense muon beam, which produces $10^{8} \mu$/s at $\pi$E5 beamline (phase I) and a new high-intensity muon beamline HiMB is providing $10^{9} \mu$/s (phase II). To achieve the proposed sensitivity, the Mu3e experiment requires excellent vertex resolution, accurate timing, and momentum measurements. These are needed to reduce the main background processes, such as accidental coincidences of tracks from Michel decays with electron-positron pairs from Bhabha scattering or photon conversion.
The proposed poster will present an overview of the Mu3e experiment, and how this sensitivity is achieved based on high voltage monolithic active pixel sensors for high spatial resolution and scintillating fibres and tiles providing precise timing information at high particle
rates.Speakers: Mrs Afaf Wasili (University of Liverpool), Afaf wasili -
235
The OLVE-HERO calorimeter prototype beam tests at CERN SPS
A project of the OLVE-HERO space detector is proposed for CR measurement in the range ${10}^{12}$-${10}^{16}$ eV and will include a large ionization-neutron 3D calorimeter with a high granularity and geometric factor of ~16 ${m}^{2}٠sr$. The 3D structure of the calorimeter will allow registering CR particles coming from different directions. As the main OLVE-HERO detector is expected an image calorimeter of a boron loading of plastic scintillator with tungsten absorber. Such a calorimeter allows to measure an additional neutron signal which will improve the energy resolution of the detector. The more importantly, the rejection power between electromagnetic and nuclear CR components will be increased by factor 30-50 in the whole energy range. The boron loading scintillator detector prototype was designed and tested at the H8 beam test area at CERN SPS during heavy ion runs in 2016 - 2018. Results of the beam tests and the corresponding Monte-Carlo simulation will be presented
Speaker: Ilyas Satyshev (JINR)
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228
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Higgs Physics: Session II - PremiereConveners: Julie Malcles (Université Paris-Saclay (FR)), stefania gori (UC Santa Cruz)
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236
Higgsstrahlung and double Higgs production at high-energy CLIC operation
The Compact Linear Collider (CLIC) is a mature option for a future electron-positron collider operating at centre-of-mass energies of up to 3 TeV. CLIC would be built and operated in a staged approach with three centre-of-mass energy stages currently assumed to be 380 GeV, 1.5 TeV, and 3 TeV. This presentation focusses on unique opportunities at the multi-TeV stages in the area of Higgs physics. Two physics studies based on full detector simulations will be discussed: Higgsstrahlung (e+e- -> ZH) and the extraction of the Higgs self-coupling from double Higgs production. The first is particularly interesting as contributions from BSM effects to the Higgsstrahlung process grow with energy. Substructure information can be used to identify fully hadronic ZH events at 3 TeV to maximise the statistical precision. B-tagging in boosted Higgs boson decays was studied for the first time for CLIC. New projections for the ZH event rate and angular distributions will be shown. The Higgs self-coupling is of particular interest: for determining the shape of the Higgs potential, and due to its sensitivity to a variety of BSM physics scenarios. At the higher-energy stages CLIC will produce Higgs boson pairs both via double Higgsstrahlung and via vector-boson fusion. Measurements of these processes lead to a determination of the Higgs self-coupling with a precision around 10%.
Speaker: Matthias Artur Weber (CERN) -
237
Measurement of Higgs to WW in the all-jet final state at CEPC √s=250 GeV
The most important pillar in the physics case of future electron-positron colliders in high energy physics is the measurement of the Higgs boson, with its main goal to precisely measure the its properties and to probe potential of associated new physics. All next generation electron positron facilities in high energy physics will make use of the Higgstrahlung Higgs production channel. The physics potential of CEPC for measurement of the cross-section times branching ratio of subdominant decay H→WW* is presented. The Higgstrahnlung Higgs production channel is used, at the center of mass energy of 250 GeV. The fully hadronic decay, containing six soft-jets in the final state is of great importance for the detector design, jet pairing and reconstruction as showing the capability of CEPC for W/Z separation. The analysis is performed in full simulation.
Speaker: Mila Pandurovic (Vinca Institute of Nuclear Sciences, University of Belgrade, Serbia) -
238
Higgs measurements at the FCC-ee
Precision measurements and searches for new phenomena in the Higgs
sector are among the most important goals in particle physics. The
large circular e+e- collider FCC-ee will provide collisions up to an
energy of 365 GeV, with extremely high luminosities. These
collisions will allow the ultimate precision on studies of the Higgs
boson couplings, mass, total width and CP parameters, as well as
searches for exotic and invisible decays.Speaker: David d'Enterria -
239
Higgs measurements at the Future Circular Collider FCC-hh
Very high energy proton-proton collisions (up to 100 TeV) provided by the FCC-hh will produce several 10^10 Higgs bosons. This will allow high precision measurements of the Higgs boson rare decays such as H-> \mu\mu, Z~\gamma, \gamma~\gamma, of the Higgs coupling to the top quark and of the Higgs self-coupling. There is a remarkable complementarity of the FCC-ee and FCC-hh colliders, which in combination offer the best possible overall study of the Higgs boson properties.
Speaker: Michele Selvaggi (CERN) -
240
Higgs physics at the LHeC and the FCC-eh
Higgs production cross sections at LHeC (FCC-eh) energies are as large as (larger than) those at future $Z-H$ $e^+e^-$ colliders. This provides alternative and complementary ways to obtain very precise measurements of the Higgs couplings, primarily from luminous, charged current DIS. Recent results for LHeC and FCC-eh, as contained in the 2020 LHeC White paper, are shown and their combination with pp (HL-LHC) cross sections is presented leading to precision comparable for some couplings to the most promising $e^+e^-$ colliders. We will show the results for the determination of several signal strengths and couplings to quarks, leptons and EW bosons, and discuss the possibilities for measuring the coupling to top quarks and its CP phase, and the search for invisible decays.
Speaker: Uta Klein (University of Liverpool (GB)) -
241
Flavor Changing Neutral Higgs Boson Meets the Top and the Tau at Hadron Colliders
We investigate the prospects for discovering a top quark decaying into
one light Higgs boson ($h^0$) along with a charm quark
in top quark pair production at the CERN Large Hadron Collider (LHC)
and future hadron colliders.
A general two Higgs doublet model is adopted to study the signature
of flavor changing neutral Higgs (FCNH) interactions with $t \to c h^0$,
followed by $h^0 \to \tau^+ \tau^-$.
We study the discovery potential for the FCNH signal and physics background
from dominant processes with realistic acceptance cuts
and tagging efficiencies.
Promising results are found for the LHC running at 13 or 14 TeV
collision energy as well as a future pp collider at 27 TeV.Speaker: Prof. Chung Kao (University of Oklahoma) -
242
Suppression of fermionic operators in the HEFT
The low-energy effective field theory for electroweak interactions -the so called Higgs Effective Field Theory (HEFT)- is studied in this talk. It embeds the Standard Model as a particular limit and parametrizes new physics deviations. We discuss some experimental resonant diboson searches and four-fermion operators analyses that seem to push the new physics scale well over the TeV. On the other hand, the more precise oblique parameter determinations allow new physics resonances in the few TeV range. This apparent contradiction is easily solved by postulating a Lagrangian of the Standard Model extension that only couples directly the new physics sector to the bosonic degrees of freedom of the Standard Model but not to the SM fermions.
Speaker: Juan José Sanz-Cillero (Universidad Complutense de Madrid) -
243
Higgs decay into a lepton pair and a photon revisited
We present new calculations of the differential decay rates for
$H\to \ell^+\ell^- \gamma$ with $\ell=e$ or $\mu$ in the Standard
Model. The branching fractions and forward-backward asymmetries, defined
in terms of the flight direction of the photon relative to the
lepton momenta, depend on the cuts on energies and invariant masses
of the final state particles.
For typical choices of these cuts we find the branching ratios
$B(H\to e \bar e \gamma)=6.1\cdot 10^{-5}$ and $B(H\to \mu \bar \mu \gamma)=6.7\cdot 10^{-5}$ and the forward-backward asymmetries
$ \mathcal{A}^{(e)}_{\text{FB}}=0.366$ and
$\mathcal{A}^{(\mu)}_{\text{FB}}=0.280$.Speakers: Mr Aliaksei Kachanovich (Karlsruhe Institute of Technology), Aliaksei Kachanovich (Karlsruhe Institute of Technology (KIT)) -
5:54 PM
Coffee Break
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244
Search for rare and lepton flavor violating decays of the Higgs boson with the ATLAS detector
The Standard Model predicts several rare Higgs boson decay channels, which have not yet been observed, but that could be enhanced in theories beyond the Standard Model. Among these are decays to light leptons, e.g. H→mumu. In addition, theories beyond the Standard Model may predict lepton-flavor violating decays of the Higgs boson. Results for these searches based on full Run-2 dataset collected at 13 TeV will be presented.
Speaker: Hanna Maria Borecka-Bielska (University of Liverpool (GB)) -
245
Searches for Higgs boson rare and invisible decays at CMS
The most recent results of the searches for rare standard model Higgs boson decays by the CMS collaboration will be presented. Searches for Higgs bosons decaying to invisible particles will also be covered.
Speaker: Vukasin Milosevic (Imperial College, Univ. of London) -
246
Exotic Higgs decays in ATLAS
Exotics decays of the Higgs boson provide a unique window for the discovery of new physics, as the Higgs may couple to hidden-sector states that do not interact under the Standard Model gauge transformations. Models predicting exotic Higgs decays to pseudoscalars can explain the galactic center gamma-ray excess, if the additional pseudoscalar acts as the dark matter mediator. This talk presents recent ATLAS searches for decays of the 125 GeV Higgs boson to a pair of new light bosons, H -> aa, where the a-bosons decay to various final states and rare Higgs decays. These searches use LHC collision data at sqrt(s) = 13 TeV collected by the ATLAS experiment in Run2.
Speaker: Christopher Robyn Hayes (University of Michigan (US)) -
247
Searches for exotic Higgs boson decays at CMS
Most recent CMS results on searches for Higgs boson decays not expected in the standard model, such as lepton-flavour-violating decays and decays to pairs of new light scalar or pseudoscalar particles, will be presented. Searches for decays with mesons in the final states, expected in the standard model but with extremely small branching ratios, will also be covered.
Speaker: Fengwangdong Zhang (UC Davis) -
248
Searches for invisible Higgs boson decays at the ATLAS experiment
In the Standard Model, the branching ratio for Higgs boson decays to invisible final states is very small, but it can be significantly enhanced in extensions of the Standard Model. This talk presents searches for Higgs boson decays to invisible final states with the full run 2 data.
Speaker: Benjamin John Rosser (University of Pennsylvania (US)) -
249
Higgs boson measurements in hadronic final states at CMS
Recent CMS measurements of Higgs boson properties in hadronic final states will be presented.
Speaker: Nick Smith (Fermi National Accelerator Lab.) -
250
Measurements and searches of Higgs boson decays to two quarks at the ATLAS experiment
Testing the couplings of the Higgs boson to fermions is an important part to understand the origin of fermion masses. The talk presents cross section measurements in Higgs boson decays to two b quarks, as well as interpretations of the measurements. It also presents a search for Higgs boson decays to two c quarks. Both analyses are based on pp collision data collected at 13 TeV.
Speaker: Marco Battaglia (University of California,Santa Cruz (US))
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236
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Neutrino Physics: Session II - PremiereConveners: Elizabeth Turner Worcester (Brookhaven National Laboratory (US)), Vit Vorobel (Charles University (CZ))
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251
Neutrino Physics with the SHiP experiment at CERN
The SHiP Collaboration has proposed a general-purpose experimental facility operating in beam dump mode at the CERN SPS accelerator with the aim of searching for light, long-lived exotic particles of Hidden Sector models. The SHiP experiment incorporates a muon shield based on magnetic sweeping and two complementary apparatuses. The detector immediately downstream of the muon shield is optimised both for recoil signatures of light dark matter scattering and for tau neutrino physics, and consists of a spectrometer magnet housing a layered detector system with heavy target plates, emulsion film technology and electronic high precision tracking. The second detector system aims at measuring the visible decays of hidden sector particles to both fully reconstructible final states and to partially reconstructible final states with neutrinos, in a nearly background free environment. Using the high-intensity beam of 400 GeV protons, the experiment is capable of integrating $2\times 10^{20}$ protons in five years, which allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutrinos with GeV-scale masses at sensitivities that exceed those of existing and projected experiments. The sensitivity to heavy neutrinos will allow for the first time to probe, in the mass range between the kaon and the charm meson mass, a coupling range for which baryogenesis and active neutrino masses can be explained. The sensitivity to light dark matter reaches well below the elastic scalar Dark Matter relic density limits in the range from a few $\mbox{MeV/c}^2$ up to $\mbox{200 MeV/c}^2$. The tau neutrino deep-inelastic scattering cross-sections will be measured with a statistics a thousand times larger than currently available, with the extraction of the $F_4$ and $F_5$ structure functions, never measured so far, and allow for new tests of lepton non-universality with sensitivity to BSM physics.
Following the review of the Technical Proposal, the Collaboration recently submitted to the CERN SPS Committee a Comprehensive Design Study. These studies have resulted in a mature proposal discussed at the European Strategy for Particle Physics Update meeting in Granada.
A measurement of charm production with a SHiP-like target interleaved with emulsion-based detectors was performed at SPS during 2019 and will be reported at this conference.Speaker: Marilisa De Serio (Universita e INFN, Bari (IT)) -
252
The ENUBET experiment
The ENUBET experiment (*) aims at demonstrating the feasibility of a ``monitored'' neutrino beam, in which the absolute normalization of the neutrino flux produced by a narrow band meson beam can be constrained at the 1% level. The electron neutrino component is determined by monitoring large-angle positrons from Ke3 decays in a 40 m long instrumented decay tunnel (tagger). The measurement of muons in the tagger and after the hadron dump allows to determine the nu_mu flux from kaons and pions respectively. In addition, in a narrow band beam (p=8.5GeV +/- 10%), the transverse position of the neutrino interaction at the detector can be exploited to determine a priori, with significant precision, the neutrino energy spectrum without relying on the final state reconstruction. These concepts can be implemented in a single facility based on standard accelerator technologies for a new generation of high precision nu_e and nu_mu cross section measurements at the GeV scale and for precision searches of Physics beyond the standard three neutrino paradigm.
We will present the optimization and performances of a 20 m long focusing transfer line allowing for a continuous measurement of Ke3 positrons at single-particle level. The (quadrupole-based) focusing system is designed to be operated with a slow extraction proton scheme where protons can be diluted over several seconds. This timing allows for the direct monitoring of muons after the hadron dump and extends the original scope of the project towards a full-fledged ``time-tagged'' neutrino beam: time-coincidences among the lepton at the source and the neutrino at the detector would enable an unprecedented purity and the possibility to reconstruct the neutrino kinematics at source on an event by event basis.
At ICHEP we will present for the first time the design of the horn-based beamline. We have recently improved the initial transfer line design by introducing an additional dipole giving an increased bending angle for momentum selection (~8.5 GeV/c mesons). It ensures a reduced background from the untagged neutrino component at the neutrino detector and an higher purity of the meson beam at the expense of a reduced meson yield. The neutrino flux reduction is compensated in this option by a horn-based focusing and a "burst slow extraction" that has been recently demonstrated experimentally at CERN-SPS in the context of the ENUBET machine studies.
This contribution will report on another major milestone: the final design of the ENUBET demonstrator for the instrumented decay tunnel that is due end 2021, and has been selected on the basis of the results of the 2016-2018 testbeams. This large detector prototype will prove the scalability and performance of the selected detector technology: an iron-scintillator modular sampling calorimeter (for e/pi separation) with a lateral light readout through WLS fibers connected to SiPMs, complemented by a photon veto system (for e/pi0 separation) made by an
inner ring of plastic scintillator trackers.(*) ENUBET is an ERC project (2016-2021, p.i. Andrea Longhin). Since March 2019 ENUBET is also a CERN Neutrino Platform experiment, approved under the name NP06/ENUBET.
Speaker: Francesco Terranova (Universita & INFN, Milano-Bicocca (IT)) -
253
Hadron production measurements for neutrino oscillation experiments at NA61/SHINE
Hadron production measurements are crucial for helping long baseline neutrino oscillation experiments constrain their beam flux uncertainties. These uncertainties represent a leading systematic uncertainty on measured neutrino oscillation parameters. At the NA61/SHINE experiment on CERN's Super Proton Synchrotron, interactions of charged hadrons with various materials relevant to neutrino production are recorded and analyzed, resulting in differential cross-sections of charged and neutral particles contributing to neutrino flux. Both thin targets and replica targets have been measured at NA61/SHINE, and more replica target measurements are forseen after CERN's Long Shutdown 2. New thin target results will be shown.
Speaker: Brant T Rumberger (University of Colorado Boulder (US)) -
254
The ESSnuSB project
Considering the relatively large value of the last measured neutrino mixing angle θ13, the way is now open to observe for the first time a possible CP violation in the leptonic sector. The measured value of θ13 also privileges the 2nd oscillation maximum for the discovery of CP violation instead of the usually used 1st oscillation maximum. The sensitivity at this 2nd oscillation maximum is significantly higher than for the 1st oscillation maximum inducing a lower influence of systematic errors. Going to the 2nd oscillation maximum necessitates a very intense neutrino beam with the appropriate energy. The world’s most intense pulsed spallation neutron source, the European Spallation Source, will have a proton linac with the unprecedented power of 5 MW and 2 GeV energy. This linac, under construction, also has the potential to become the proton driver of the world’s most intense neutrino beam with very high potential to discover and well measure a neutrino CP violation. The physics performance of that neutrino Super Beam in conjunction with a megaton underground Water Cherenkov neutrino detector installed at a distance of about 500 km from ESS has been evaluated. In addition, the choice of such detector will extent the physics program to proton–decay, atmospheric neutrinos and astrophysics searches. The ESS proton linac upgrades, the accumulator ring needed for proton pulse compression, the target station optimization and the physics potential are described. In addition to neutrinos, this facility will also produce at the same time a copious number of muons which could be used by a low energy nuSTORM facility, a Neutrino Factory or/and a muon collider. The ESS neutron facility will be fully ready by 2025 at which moment the upgrades for the neutrino facility could start.
This project is supported by the COST Action CA15139 "Combining forces for a novel European facility for neutrino-antineutrino symmetry-violation discovery" (EuroNuNet). It has also received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419.Speakers: Dr Budimir Klicek (Ruder Boskovic Institute, Zagreb), Dr Marcos Dracos (Centre National de la Recherche Scientifique (FR)) -
255
Detecting and studying high-energy neutrinos with FASERnu at the LHC
FASER, the Forward Search Experiment at the Large Hadron Collider (LHC), is an experiment aiming to search for light, weakly-interacting new particles. The particle detector will be located 480 m downstream of the ATLAS interaction point. In addition to searches for new particles, we proposed a new detector (FASER$\nu$) to study neutrinos at the highest man-made energies and got approval by the CERN Research Board in December 2019. To date, neutrino cross-section data exist up to a few 100 GeV with accelerator-based neutrino beams. With FASER$\nu$, the neutrino cross-sections will be measured in the currently unexplored energy range between a few 100 GeV and 6 TeV. In particular, electron-neutrino and tau-neutrino cross sections will be measured at the highest energy ever. Furthermore, the channels associated with heavy quark (charm and beauty) production could be studied. As a feasibility study, we performed a test run in 2018 at the proposed detector location with a 30-kg lead/tungsten emulsion detector and collected data of 12.5 fb$^{-1}$. By analyzing the data, we selected several neutrino interaction candidates and are performing a multivariate analysis for the separation from the background towards a first detection of neutrinos at the LHC. From 2021 to 2023 (2024) during Run 3 of the LHC, we will deploy an emulsion detector with a target mass of 1.2 tons, possibly coupled with the FASER magnetic spectrometer, which would yield roughly 1,300 $\nu_e$, 20,000 $\nu_{\mu}$, and 20 $\nu_{\tau}$ interacting in the detector. Here, we present an overview and the status of the FASER$\nu$ program, as well as the analysis for the neutrino detection in the 2018 data.
Speaker: Dr Akitaka Ariga (Universitaet Bern (CH)) -
256
Hadron-argon cross-section measurements in ProtoDUNE-SP
The single-phase liquid argon ProtoDUNE detector (ProtoDUNE-SP) is located at CERN's neutrino platform facility and it serves as a prototype to validate the technology for the 10-kton fiducial mass liquid argon detectors for the DUNE experiment. ProtoDUNE-SP was exposed to a variety of test-beam particles (electrons, muons, pions, kaons, and protons) towards the end of 2018 collecting data in a broad range of momenta, from 0.3 - 7 GeV/c. These cross-sections will improve the understanding of final-state interactions in neutrino-argon cross-sections. The progress of the analyses towards the cross-section measurements on argon from the test-beam data collected at protoDUNE-SP will be presented.
Speaker: Heng-Ye Liao
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251
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