8th International Conference on New Frontiers in Physics (ICNFP 2019)
The International Conference on New Frontiers in Physics aims to promote scientific exchange and development of novel ideas in science with a particular accent in interdisciplinarity. The conference will bring together worldwide experts and promising young scientists working on experimental and theoretical aspects of particle, nuclear, heavy ion and astro-particle physics and cosmology, with colleagues from other disciplines, for example solid state physics, mathematics, mathematical physics, quantum optics and other.
The conference will be hosted in the Conference Center of the Orthodox Academy of Creta (OAC), an exceptionally beautiful location only a few meters from the mediteranean sea.
The pictures of the conference are now available via the link.
The main features of diffractive processes and QCD inspired models are overviewed. The following topics are discussed: (1) Diagonal (elastic) diffraction, which shows that the underlying theory is non-abelian;
(2) Quantum mechanics and general features of the off-diagonal diffractive processes; (3) Color dipole description of diffraction; (4) triple-Regge phenomenology; (5) what do we learn about hadron structure from soft diffraction? Why interaction of Pomerons is so weak?
(6) Diffraction near the unitarity bound: why the diffractive cross stops rising;
(7) “Hard diffraction” turns out to be semisoft-semihard;
(8) factorization of short- and long-distance interactions is severely broken in hard diffractive hadronic collisions;
(9) examples: diffractive DIS, diffractive Drell-Yan, diffractive production of gauge bosons, diffractive heavy flavors, diffractive Higgs production.
The last decades of high energy physics revealed, that in ultra-relativistic
ion-ion collisions, a strongly interacting quark gluon plasma (sQGP) is created.
Varying the collision energy and system size allows for the investigation of the
phase diagram of QCD matter at different baryochemical potentials and
temperatures. Varying the system size may also reveal the influence of system
lifetime on the final state observables. In the recent years, it became a more
and more important question how the matter created in small but energetic
collision systems behaves, and the extent of similarity between small and large
systems is investigated at several experiments. One of the most important
results of the recent years was the elliptic and triangular flow in p+Au, d+Au
and He3+Au collisions at sqrt(sNN)=200 GeV at PHENIX. In this talk we will
review these results, along with a few other important flow measurements from RHIC and LHC.
TBA
The storage of freshly produced radioactive particles in a storage ring is a straightforward way to achieve the most efficient use of such rare species as it allows for using the same rare ion multiple times. Employing storage rings for precision physics experiments with highly-charged ions (HCI) at the intersection of atomic, nuclear, plasma and astrophysics is a rapidly developing field of research.
Until very recently, there were only two accelerator laboratories, GSI Helmholtz Center in Darmstadt, Germany (GSI) and Institute of Modern Physics in Lanzhou, China (IMP), operating such facilities. The experimental storage ring ESR at GSI and the experimental cooler-storage ring CSRe at IMP are able to store, cool and manipulate ions beams at energies of 400 A MeV, corresponding to b=0.6. The ESR is capable to slow down ion beams to as low as 4 A MeV (b=0.1).
Thanks to the fascinating results obtained at ESR and CSRe as well as to versatile experimental opportunities, there is now an increased attention to the research with ion-storage rings worldwide. Furthermore, experimental opportunities are being now dramatically enhanced through construction of dedicated low-energy storage rings, which enable stored and cooled secondary HCIs in previously inaccessible low-energy range. The first such facility, CRYRING, has just been constructed at GSI to receive decelerated beams of HCIs from ESR. Dedicated ring facilities are proposed for ISOLDE at CERN, TRIUMF, LANL, and JINR. In this contribution, some highlight research programs at present and future heavy-ion storage rings will be presented.
TBA
Will review the current experimental status of the study on nucleon spin structure.
Then present recent results from JLab and discuss the near-term plan.
TBA
There is considerable phenomenological insight into the flavor compositions of nucleon electromagnetic form factors from elastic electron scattering on both the proton and the neutron at low and moderate momentum transfers. The flavor contents extracted so far from the corresponding world data sets impose severe tests on any theoretical description of the electromagnetic structure of the nucleons.
I shall discuss the predictions for covariant electric and magnetic form factors by a relativistic constituent-quark model and compare them to phenomenology as well as some results from lattice quantum chromodynamics. The main findings are that valence-quark contributions play the essential roles up to momentum transfers of q^2 ~ 4 GeV^2 and additional degrees of freedom, e.g., sea-quark effects, are still absent or at least negligible in this domain.
The same kind of studies is extended to the Δ and the hyperons showing interesting effects depending on the flavor structures of the particles belonging to either singlet, octet, and decuplet flavor multiplets as well as their admixtures.
The DArk Matter Particle Explorer (DAMPE) is a high-performance space particle detector launched in orbit in 2015 by a collaboration of Chinese, Italian and Swiss scientific institutions, coordinated by the Chinese Academy of Sciences. It consists of a high-resolution segmented BGO electromagnetic calorimeter with a depth of 32 radiation lengths, a silicon-tungsten tracker-converter with an angular resolution below 0.2°, an anti-coincidence shield and ion detector, and a neutron detector. The detector characteristics and performance, and the latest observations of cosmic electrons up to 5 TeV, protons and nuclei up to 100 TeV and gamma-rays up to 10 TeV will be presented.
A convincing observation of neutrino-less double beta decay (0νDBD) relies on the possibility of operating high-energy resolution detectors in background-free conditions.
Scintillating cryogenic calorimeters are one of the most promising tools to fulfill the requirements for a next-generation experiment. Several steps have been taken to demonstrate the maturity of this technique, starting form the successful experience of CUPID-0.
The CUPID-0 experiment collected 10 kg*y of exposure, running 26 Zn82Se crystals during two years of continuous detector operation. The complete rejection of the dominant alpha background was demonstrated, measuring the lowest counting rate in the region of interest for this technique. Furthermore, the most stringent limit on the Se-82 0νDBD was established.
In this contribution we present the final results of CUPID-0 Phase I, including a detailed model of the background and the measurement of the 2νDBD half-life.
Boris Sharkov
Joint Institute for Nuclear Research, Dubna, Moscow region, 141980 Russia.
National Research Nuclear University MEPhI, 115409, Moscow, Kashirskoe shosse, 31.
Construction of new generation of heavy ion accelerator facilities is progressing well and forefront accelerator technologies are under development in JINR for low energy as well as for relativistic heavy ion nuclear physics.
This presentation outlines ongoing activities on development of heavy ion accelerator facilities, providing high-brightness beams capable of generating intense beams of RI as well as for research into extreme state of nuclear matter. Manifested facilities goals are pushing the “intensity” and the “precision frontiers” to the extremes when accelerating full range of ion beam species from p+ to U to highest beam intensities and luminosities.
Sophisticated beam manipulation methods, stochastic and electron cooling of ion beams, also applicable to the secondary radioactive beams of exotic nuclei is under discussion.
Consideration is focused on the recent achievements in high power linear accelerator injection chains, rapid cycling superconducting magnets of large synchrotron rings, ultra-high dynamic vacuum technologies, efficient accumulation and cooling of intense heavy ion beams.
TBA
TBA
Full list of authors: P.N. Ostroumov, S. Cogan, K. Fukushima, S.H. Kim, S. Lidia, F. Marti, T. Maruta, A.S. Plastun, J. Wei, T. Yoshimoto, T. Zhang and Q. Zhao,
The Facility for Rare Isotope Beams in Michigan State University includes a continuous wave (CW) superconducting (SC) driver linac capable to accelerate any ion beam from oxygen to uranium above 200 MeV/u. The first segment of the FRIB linac, composed of 15 cryomodules, was successfully commissioned with beam. Detailed study of the beam parameters demonstrated good consistency with the original design parameters. Four ion beam species, Ne, Ar, Kr and Xe, were accelerated up to 20.3 MeV/u with 100% transmission and no detectable beam losses. High-power equivalent beams were delivered to the beam dump in two modes: pulsed and CW. In pulsed mode, the peak intensity of argon beam was 14.8 pA at 3% duty factor which constitutes 30% of the FRIB design intensity for this particular ion beam. A CW argon beam was accelerated, demonstrating that the FRIB linac in its current configuration is the highest energy CW SC hadron linac in the world.
*Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
We present new results for fluctuations of the baryon number for QCD with
Nf=2+1 quark flavours at non-zero temperature and chemical potential [1].
These are extracted from a framework based on a combination of lattice QCD
and Dyson-Schwinger equations. In previous works ([2], see [3] for a review)
we found a critical end point in the region ($T^c,\mu_B^c$)=(120,500) MeV.
We discuss the changes of ratios of fluctuations up to fourth order along
and below the transition line for temperatures and baryon chemical potential
up to and beyond the critical end point.
Comparing with preliminary STAR data for the skewness and kurtosis ratios,
our results are compatible with the scenario of a critical end point at
large chemical potential and slightly offset from the freeze-out line.
We also discuss the caveats involved in this comparison.
[1] P.Isserstedt, M.Buballa, C.S.Fischer, P.Gunkel, arXiv:
[2] C.S.Fischer, J.Luecker and C.A.Welzbacher, Phys. Rev. D 90 (2014) no.3, 034022
[3] C.S.Fischer, Prog. Part. Nucl. Phys. 105 (2019) 1
Low-energy QCD at finite temperatures and baryochemical densities predicts a phase transition from a chiral symmetry broken hadronic phase to a chirally restored quark-gluon plasma phase. In this talk the two and three quark flavor chiral phase structure with and without an axial U(1)-symmetry breaking is the major focus. The current status of low-energy QCD effective models is briefly summarized. Non-perturbative quantum fluctuations that are of particular importance in the vicinity of any phase transition are taken into account with the functional renormalization group method. The influence of vacuum and thermal fluctuations of quarks and mesons on the chiral phase structure is investigated in a systematic manner and confronted with corresponding mean-field approximations.
Fluctuations of conserved charges such as baryon number, electric charge and strangeness [1,2] may provide a test for completeness of states in lattice QCD for three light flavors [3-7]. We elaborate on the idea that the corresponding susceptibilities can be saturated with excited baryonic states with an underlying quark-diquark structure with a linearly confining interaction. Using Polyakov-loop correlators we show that in the static limit, the quark-diquark potential coincides with the quark-antiquark potential in marked agreement with recent lattice studies. We thus study in a quark-diquark model the baryonic fluctuations of electric charge, baryon number and strangeness: $\chi_{BQ}$, $\chi_{BB}$ and $\chi_{BS}$; by considering a realization of the hadron resonance gas model in the light flavor sector of QCD [8]. These results have been obtained by using the baryon spectrum computed within a relativistic quark-diquark model, leading to an overall good agreement with the spectrum obtained with other quark models and with lattice data for the fluctuations.
[1] S. Borsanyi, Z. Fodor, S. D. Katz, S. Krieg, C. Ratti, and K. Szabo, JHEP 01 (2012) 138.
[2] A. Bazavov et al. (HotQCD Collaboration), Phys. Rev. D86, 034509 (2012).
[3] E. Ruiz Arriola, L.L. Salcedo and E. Megias, Acta Phys. Polon. B45 (2014) 2407-2453.
[4] E. Ruiz Arriola, L.L. Salcedo, E. Megias, Acta Phys. Polon. Supp. 8 (2015) 2, 439.
[5] E. Megias, E. Ruiz Arriola, L.L. Salcedo, Phys. Rev. D94 (2016) 9, 096010.
[6] E. Ruiz Arriola, W. Broniowski, L.L. Salcedo, E. Megias, arXiv:1612.07091[hep-ph].
[7] E. Megias, E. Ruiz Arriola, L.L. Salcedo, Acta Phys. Polon. Supp. 11 (2018) 563.
[8] E. Megias, E. Ruiz Arriola, L.L. Salcedo, Phys. Rev. D99 (2019) 7, 074020.
We point out a distinction, in gauge theories with matter in the fundamental representation, between color confinement and a stronger version of confinement, which we call “separation of charge” confinement. The latter is a generalization of the Wilson area-law criterion to gauge+matter theories . In gauge-Higgs theories, we show that the transition (which is not necessarily a thermodynamic transition) between separation-of-charge confinement and color confinement coincides with the spontaneous breaking of a certain global symmetry in the Higgs sector, known as custodial symmetry.
The branching of center vortices in SU(3) Yang-Mills theory in maximal center gauge is analyzed. When properly normalized, one can define a branching probability that turns out to be independent of the lattice spacing (in the limited scaling window studied here). The branching probability shows a rapid change at the deconfinement phase transition which is much more pronounced in space slices of the lattice as compared to time slices. Though not a strict order parameter (in the sense that it vanishes in one phase) the branching probability is thus found to be a reliable indicator for both the location of the critical temperature and the geometric re-arrangement of vortex matter across the deconfinement phase transition
Title: Neutrino CP Violation with the European Spallation Source neutrino Super Beam project.
After measuring in 2012 a relatively large value of the neutrino mixing angle θ13, the door 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 about three times 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 aproton linac with 5 MW power and 2 GeV energy. This linac, under construction, alsohas the potential to become the proton driver of the world’s most intense neutrino beam with very high potential to discover 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 muon collider. The ESS neutron facilitywill be fully ready by 2023 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"and the European Union’s Horizon 2020 research and innovation program under grant agreement No 777419.
The targeted treatment of cancerous tumors by alpha-emitting radionuclides has shown remarkable efficacy in recent clinical trials [1]. It is likely that this treatment option will ultimately be applicable to a wide range of cancers and other diseases, subject to the development of specific carrier molecules. Currently Ac-225 is being produced from natural ingrowth in existing stocks of Th-229. However, future wide application for radiotherapy will require many orders of magnitude more radionuclide than can currently be produced. Consequently, following up on earlier work at the European Commission's Joint Research Centre (JRC) [2], we are pursuing various alternative production methods. In this paper, an overview of internal radiotherapy with alpha emitters is given, along with recent clinical experience, as well as possible schemes for the large-scale production of Ac-225 using different target materials and irradiation facilities.
[1] A. Morgenstern et al., “An overview of targeted alpha therapy with 225actinium and 213bismuth,” Curr. Radiopharm. 11 (2018) 200.
[2] C. Apostolidis et al., “Cyclotron production of Ac-225 for targeted alpha therapy,” Appl. Radiat. Isot. 62 (2005) 383.
TBA
DERICA (Dubna Electron-Radioactive Ion Collider fAcility) is the new rare isotope facility project under development at JINR *. DERICA is proposed as the next step in RIB facilities development and construction. It is planned that in the DERICA project the RIBs produced by the DERICA Fragment Separator, are stopped in a gas cell, accumulated in the ion trap and then transferred to the ion source/charge breeder, creating the highest possible charge state for the further effective acceleration (system {gas cell - ion trap - ion source/charge breeder}). From the accelerator point of view, DERICA facility will include CW driver LINAC-100 (energy up to 100 MeV/u for Uranium and up to 50 MeV/u for Calcium ions), fragment separator, re-accelerator LINAC-30 (energy up to 30 MeV/u with the possibility of broad regulation), fast ramping ring (energy <300 MeV/u), collector ring and electron storage ring. Driver LINAC-100 as a complex facility consists of the normal-conducting front-end (or two front-end separately for heavy and light ions) and the main superconducting part. It was proposed to use one or two strippers to increase the charge state of heavy ion beam and to decrease length and cost of LINAC-100. The general concept of DERICA accelerator complex, LINAC-100 and LINAC-30 layout and results of the beam dynamics simulation will be presented in this report.
Given the solution of Nf=2 QCD on the lattice
with a chirally symmetric Dirac operator
and symmetry classification of the QCD Lagrangian
we identify the following three physically different regimes
of QCD.
Up to the pseudo-critical temperature Tc
the QCD matter is a hadron gas with broken chiral symmetries.
From the hadron gas regime below Tc there is a crossover to
a regime with chiral and chiral-spin symmetries, where chirally
symmetric quarks are bound by the chromo-electric component
of gluonic field without the chromo-magnetic contributions. From
temperatures 500 - 550 MeV there is a
smooth evolution to the quark-gluon plasma regime with weakly interacting
quarks and where only chiral symmetries survive.
We discuss dense cool QCD where a region with spatially inhomogeneous condensates may emerge. In that case, QCD phase diagram may exhibit a Lifshitz regime, which can appear either instead of, or in addition to Critical End Point. We study the Lifshitz regime using a combination of large-N expansion and numerical lattice simulations.
Statistical methods for data treatment with and without signal (ATLAS+CMS)
The ALICE detector and trigger performance during the LHC Run2 will be reviewed in this talk.
Heavy-flavour quarks are considered to be effective probes of the Quark-Gluon Plasma (QGP) produced in ultra-relativistic heavy-ion collisions. Since heavy-flavour quarks have a large mass, their production takes place mostly in initial hard scatterings, and it is calculable using perturbative QCD. Thus, heavy flavour quarks can be considered as ideal self-generated penetrating probes of the created medium and utilized to investigate mass-dependent properties of in-medium parton energy loss or cold nuclear matter.
In particular the measurement of heavy-flavour jet production in pp, besides beeing a natural reference for Pb-Pb studies, allow testing pQCD calculations and models of charm fragmentation in vacuum. In addition, similar measurements in p-Pb collisions allow assessing the importance of cold nuclear matter effects. The ALICE experiment at the LHC exploits its excellent particle tracking capabilities, that allow for a precise jet reconstruction and for the identification of D and B-hadron decay vertices, displaced hundreds of micrometers from the primary interaction vertex. In the talk we will report on our heavy-flavour jet measurements done in p-Pb and pp collisions.
Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarizes recent ATLAS results on searches for supersymmetric squarks and gluinos, including third generation squarks produced directly or via decay of gluinos. Some models of supersymmetry, including models with R-parity violation, predict that the lightest supersymmetric particle will decay back into Standard Model particles, removing the classical missing transverse momentum signature. These more difficult signatures have also been investigated, and results from these searches are presented.
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. From February to July 2018, the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$, and Belle II has recorded a data sample of about 0.5 fb$^{-1}$. Main operation of SuperKEKB has started in March 2019.
We use the early Belle II data to characterize the performance of the detector regarding the tracking of charged particles, the reconstruction of known resonances, and the capability of identifying displaced decay vertices.
A first benchmark towards analysing time-dependent CP violation consists in the measurement of the lifetime of B mesons and of the $B^0-\bar B^0$ mixing frequency. We present the first results, based on samples of B mesons that decay to hadronic and semileptonic final states. We further present estimates of the sensitivity to $\beta$ in the golden channels $B\to c\bar cs$ and in the penguin-dominated modes $B^0\to\eta’ K^0$, $\phi K^0$, $K_S\pi^0(\gamma)$. A study of the time-dependent analysis of $B^0\to\pi^0\pi^0$, relevant for the measurement of $\alpha$, and feasible only in the clean environment of an $e^+ e^-$ collider, will also be given.
Belle II can also measure $\gamma$, the third and least well known CKM angle, through the interference between $B^+\to D^0 K^+$ and $B^+ \to \bar D^0 K^+$ decays, which occurs if the final state of the charm-meson decay is accessible to both the $D^0$ and $\bar D^0$ mesons. We will also discuss the precision that Belle II will be achieved in this measurement.
Precision electroweak measurements with the ATLAS detector
In March 2017 the first set of radioactive ion beams (RIBs) was obtained from the new in-flight fragment separator ACCULINNA-2 operating at the primary beam line of the U-400M cyclotron. A lot of additional work was done before the first experimental run which was carried out in fall 2017. Namely, the new experimental hall of the setup (the linear part of the radioactive beam line) was fully completed providing all communications and equipment (electricity, air conditions, water cooling, reaction chamber, detectors, electronics etc). All observed RIB characteristics are in a good agreement with expected estimations. New separator provides high quality secondary beams, and it opens new opportunities for experiments with RIBs (Z < 36) in intermediate energy range 10-50 AMeV. To expand significantly RIB intensities, its assortment (Z ~ 54) and available energies (up to ~ 150 AMeV) the new heavy ion driver and more powerful fragment separator are obviously need. Possible design of the setup and related physical tasks will be reported as well.
Experience of RIBs Research at RIPS facility at RIKEN
In this talk recent progress on the phase structure of QCD and transport processes with the functional renormalisation group are reviewed. I present an update of the phase boundary that is in agreement with recnet lattice results. At larger density we also find indictations for an inhomgeneous phase as well as a critical end point.
The method is also used for the computation of transport coefficients such as the shear viscosity as well as general real-time correlation functions. This input is then used for computing flow coefficients, particles yields and fluctuation observables with QCD-assisted hydrodynamics and transport at finite temperature and density.
During the last years it has become possible to address the cold and dense regime of QCD directly for
sufficiently heavy quarks, where combined strong coupling and hopping expansions are convergent and a
3d effective theory can be derived, which allows to control the sign problem either in simulations or by fully
analytic calculations. In this
contribution we review the effective theory and study the $N_c$-dependence of the nuclear liquid gas transition, as well as the equation of
state of baryonic matter.
We find the transition to become more strongly first order with growing $N_c$, suggesting that in the large
$N_c$ limit its critical endpoint moves to high temperatures to connect with the deconfinement transition. Furthermore,
to leading and next-to-leading order in the strong coupling and hopping expansions, respectively, the pressure is found
to scale as $p\sim N_c$, which is a defining property of quarkyonic matter.
The Functional Renormalization Group (FRG) can be used to calculate spectral functions from analytically continued FRG flow equations for two-point correlation functions. Here we report on the current status of applying this aFRG framework to the calculation of vector and axial-vector meson spectral functions in effective hadronic theories at finite temperature and density. Their medium modifications have a direct impact on the electromagnetic spectral function and thus on thermal dilepton rates in the range of invariant-mass values of up to about 1 GeV. Because chiral symmetry restoration at finite temperature and/or density is reflected in these spectral functions, this can be exploited to search for experimental signatures, from heavy-ion collisions at HADES energies and later with CBM at FAIR, of a chiral first-order phase transition and the associated critical endpoint (CEP) in the phase diagram of QCD.
Some years ago, relying on standard functional manipulations, a new property of QCD fermionic Green’s functions has been put forth and called effective locality. This feature of QCD is non-perturbative, as resulting from a full integration of the gluons degrees of freedom. At least at quenching and a mild eikonal approximation, the relation of effective locality to dynamical chiral symmetry breaking will be examined. In particular interesting connections to Quark Flavour Dynamics will be discussed.
Using previously described functional techniques for some non–perturbative, gauge invariant, renormalized QCD processes, a simplified version of the amplitudes — in which forms akin to Pomerons naturally appear — provides fits to ISR and LHC–TOTEM pp elastic scattering data.
Those amplitudes rely on a specific function φ(b) which describes the fluctuations of the transverse position of quarks inside hadrons.
Local formulations of quantum field theory imply that gauge theory propagators can potentially contain generalised infrared poles. In this talk I will outline the theoretical significance of these components, and report on recent lattice fit results for the gluon propagator.
Very successful operation of the CMS detector for almost 10 years allowed the CMS collaboration to produce a large number of results,
from the discovery of the Higgs boson and the measurement of its properties, to setting stringent limits on the existence of physics beyond the Standard Model.
This talk will briefly summarize some of the experimental challenges and give an overview of some of the main physics results delivered so far.
This includes results on the Higgs boson coupling to fermions, the search for Supersymmetry in several final state topologies, and other selected searches for particles beyond the Standard Model.
A brief overview of the preparations for an upgrade to the experiment for operation at the High Luminosity LHC starting in the mid-2020s also will be reported.
TBA
The strong scalar fields in a nuclear medium naturally lead to changes in the structure of the bound nucleons. This idea has been developed into a quantitatively successful theory of nuclear structure, which we will briefly review. However, it is vital to test the underlying idea, which is really a paradigm shift for nuclear science. The EMC effect is one of those ways and we will explain why the measurement of the polarized EMC effect in particular would be extremely valuable.
A historical overview of parity violating electron scattering will be provided, followed by a motivation and description of ongoing experiments and future prospects.
Traditional nuclear physics regards the nucleus as being composed of bound nucleons and mesons. This picture has had significant success in describing the properties of nuclei across the chart of nuclides. However, the fundamental theory of the strong interaction is QCD, where quarks and gluons are the elementary degrees of freedom. Deep inelastic scattering experiments have long suggested that a nucleon-meson based picture of the nucleus is incomplete. Indeed the observation of the EMC effect [1] has provided an indication for explicit QCD effects in nuclei.
The EMC effect is the observation that the parton distribution functions (PDFs) for nuclei are different than the incoherent sum over the PDFs of the constituent nucleons and suggested that the structure of the nucleons may be different when bound together in a nucleus. Since the original discovery in 1983, there has been a large program of measurements at several laboratories, such as CERN, Fermilab, SLAC, DESY, and Jefferson Lab (JLab), aimed at understanding the properties and probing the origin of the nuclear dependence of inelastic structure functions, covered in detail in several reviews [2,3,4,5].
Since the first observation of the EMC effect, many theoretical models have been proposed and can be subdivided into two categories. One takes care only of “traditional” nuclear physics effects, using convolution models including binding effects with spectral functions corresponding to realistic two- and three-body nuclear interactions. The other category invokes more exotic explanations, such contributions of six or nine quark bags, or medium modification of the internal structure of the nucleons such as “nucleon swelling” or suppression of point-like nucleon configurations.
Our work points to merge “traditional” nuclear physics in a Poincare' covariant framework through a Poincare' covariant spin-dependent spectral function [6,7,8]. It is based on the light-front (LF) Hamiltonian dynamics [9, 10] and is a useful tool for a correct relativistic treatment of nuclear structure, suitable for the study of deep inelastic scattering (DIS) or semi-inclusive deep inelastic scattering (SIDIS) processes at high momentum transfer [11,12,13]. Indeed the Bakamjian-Thomas construction [14] of the Poincare' generators allows one to embed the successful phenomenology for few-nucleon systems in a Poincare' covariant framework. In particular we study the 3He nucleus and our preliminary results for the EMC effect in 3He will be presented.
The LF spectral function for a three-fermion system, as the 3He, depends on the energy ε of the spectator subsystem and on the LF momentum ϰ of the knocked out particle in the intrinsic reference frame of the (particle - spectator pair) cluster. It is built up from the overlaps of the ground eigenstate of a proper mass operator for the system [6,7,8] and the tensor product of a plane wave for the particle times the fully interacting state for the spectator. The use of the momentum ϰ allows one to take care of macrocausality [9] and to introduce a new effect of binding in the spectral function. The LF spectral function fulfills normalization and momentum sum rule at the same time.
We aim to provide for the first time a Poincare' covariant calculation of the nuclear part of the EMC effect for the trinucleon system (both 3He and tritium), so that one can safely investigate genuinely QCD-based effects, as effects of non-nucleonic degrees of freedom or modifications of nucleon structure in nuclei, needed for reconciling experimental results and theoretical description.
References
[1] Aubert J.J. et al. (European Muon Collaboration), Phys. Lett. B 123, 275–278 (1983).
[2] Geesaman D.F., Saito K. and Thomas A.W., Ann. Rev. Nucl. Part. Sci. 45, 337–390 (1995).
[3] Malace S., Gaskell D., Higinbotham D.W. and Cloet I., Int. J. Mod. Phys. E 23, 1430013 (2014).
[4] Hen O., Miller G.A., Piasetzky E. and Weinstein L.B., Rev. Mod. Phys. 89, 045002 (2017).
[5] I.C. Cloet (Argonne) et al., arXiv:1902.10572.
[6] Del Dotto A., Pace E., Salme' G. and Scopetta S., Phys. Rev. C 95(1), 014001 (2017).
[7] Scopetta S., Del Dotto A., Kaptari L., Pace E., Rinaldi M., Salme' G., Few Body Syst. 56, 425 (2015).
[8] Pace E., Del Dotto A., Kaptari L., Rinaldi M., Salme' G., Scopetta S., Few Body Syst. 57, 601 (2016).
[9] Dirac P.A.M., Rev. Mod. Phys. 21, 392 (1949).
[10] Keister B.D. and Polyzou W.N., Adv. Nucl. Phys. 20, 225 (1991).
[11] Arrington J., Katramatou A.T., Petratos G.G. and Ransome R.D., 2010 Jefferson Lab Experiment E12-10-103 URL https://www.jlab.org/exp_prog/proposals/10/PR12-10-103.pdf
[12] Gao H., Chen J.P., Jiang X., Peng J.C. and Qian X,, 2009 Jefferson Lab Proposal PR12-09-014 URL https://www.jlab.org/exp_prog/proposals/09/PR12-09-014.pdf
[13] Chen J.P., Qiang Y. and Yan W., 2011 Jefferson Lab Proposal PR12-11-007 URL https://www.jlab.org/exp_prog/proposals/11/PR12-11-007.pdf
[14] Bakamjian B. and Thomas L.H., Phys. Rev. 92, 1300 (1953).
TBA
TBA
The next generation of nuclear physics research will require advanced exotic beam facilities based on heavy-ion drivers. Exotic beams of rare nuclei will be produced via fragmentation and fission reactions resulting from a high-energy heavy-ion beam hitting a target. A large aperture fragment separator with superconducting magnets is needed for capture, selection, and transport of rare isotopes for experiments. For rare isotope registration the multi-stage separation is required to provide reasonable rates in detectors located in an analyzing stage. So, the recent experiment devoted to explore the $^{60}$Ca region at the RIKEN RIBF facility [1] demonstrated a necessity to have three-stage separation to approach the neutron-dripline in the calcium region. Another important aspect according to the LISE$^{++}$ code calculations [2] in these new research is multi-step reactions taking into account. Momentum compression technique applied in a fragment-separator wedge-selection section and rare isotope beams slowing down line in front of a gas-cell will be discussed.
References:
TBA
TBA
We present a relativistic constituent-quark model extended to describe all known baryons on a uniform basis. The corresponding Poincaré-invariant mass operator relies on a linear confinement and a hyperfine interaction derived from Goldstone-boson exchange. The relativistic three-quark system is solved along modified Faddeev equations adapted to treat long-range interactions. While the spectroscopy of baryons with u, d, and s flavors has been discussed before, we here focus primarily on the spectra of charm and beauty baryons, which have recently become amenable to new measurements especially at LHCb. Beyond the ground states of Λ, Σ, Ξ, and Ω baryons, containing c and b flavors, we also predict their first few excitations, which are expected to be manifested by future experiments.
From a UV-complete top-down holographic dual of large-N thermal QCD at finite gauge coupling, we discuss a variety of topics like obtaining a lattice-compatible T_c, conformal anomaly, lattice/PDG-compatible glueball/meson spectroscopy and glueball-to-meson decays, speed of sound, (lattice-compatible) shear viscosity(eta)-to-entropy density ratio's variation with temperature, bulk viscosity(zeta) and a zeta/eta bound inclusive of the non-conformal corrections appearing at NLO in N. Time permitting, I will discuss some Mathematical aspects relevant to the aforementioned results (G-structures, etc.).
We study various topological objects corresponding to baryons in holographic QCD [1,2,3]. The holographic QCD is constructed with D4 and D8-branes in the superstring theory, and is equivalent to 1+3 dimensional QCD in an infrared region. We investigate instantons and monopoles topologically appearing in holographic QCD in two-flavor case.
[1] T. Sakai and S. Sugimoto, Prog. Theor. Phys. 113 (2005) 843-882.
[2] K. Nawa, H. Suganuma and T. Kojo, Phys. Rev. D75 (2007) 086003.
[3] H. Hata, T. Sakai, S. Sugimoto and S. Yamato, Prog. Theor. Phys. 117 (2007) 1157.
The production of prompt isolated photons, W-bosons and Z-bosons in proton-proton collisions provides a stringent test of perturbative QCD and yields important information about the parton distribution functions (PDFs) for quarks within the proton. In this talk, we present precision measurements of these final states across four different proton-proton centre-of-mass energies using data collected by the ATLAS experiment. The measurements are compared with (next-to-)next-to-leading-order QCD cross-section calculations and different parton distribution functions. Measurements of the isolated-photon plus two jets and the inclusive isolated-photons cross sections at sqrt(s)=13 TeV are presented, along with the ratio of photon cross sections at sqrt(s)=8 and sqrt(s)=13 TeV. The results are compared with state-of-the-art theory predictions, indicating several interesting discrepancies. We report measurements of fiducial integrated and differential cross sections for inclusive W+, W- and Z boson production at sqrt(s)=2.76 and sqrt(s)=5.02 TeV. Measurements of the W+ and W- cross sections at sqrt(s) = 8 TeV, in bins of the absolute lepton rapidity, and the associated charge asymmetry are also presented. Finally, a measurement of Z+jet production at sqrt(s) = 8 TeV is also presented.
TBA
TBA
In recent years precision optics together with strong magnetic fields have become key ingredients for fundamental physics experiments searching, for example, for vacuum magnetic birefringence and for axions and/or axion-like particles. Vacuum magnetic birefringence (polarisation dependent refractive index) is a macroscopic non-linear electrodynamic effect in vacuum predicted as a consequence of the formulation of the Euler-Kockel-Heisenberg effective Lagrangian, first proposed in 1935, which takes into account electron-positron fluctuations. A direct laboratory observation of vacuum magnetic birefringence is still lacking today due to its minute value: ∆n = 4x10e-24 @ B = 1T. Axions and axion-like particles are light neutral hypothetical bosons which could couple to two photons through the Primakoff effect. The existence of these hypothetical particles could solve the strong CP problem and are good dark matter candidates. I will describe some recent experimental results and proposals regarding these two areas of research. Key experimental ingredients in such researches are a Fabry-Perot interferometer, an intense magnetic field and a time-dependent effect.
TBA
TBA
TBA
After the discovery of the Higgs boson in summer 2012, the understanding of its properties has been a high priority of the ATLAS physics program. This talk presents measurements of differential cross sections, of spin/CP properties, of the Higgs mass, as well as indirect constraints on the Higgs boson width based on pp collision data taken at 13 TeV with the ATLAS experiment.
This presentation summarizes recent results on the properties of the BEH boson from the CMS experiment obtained with the Run 2 dataset. This will cover updates on the couplings of the boson as well as differential measurement of its production, including Simplified Template Cross Section measurements.
After the discovery of the Higgs boson in summer 2012, the understanding of its properties has been a high priority of the ATLAS physics program. The couplings of the Higgs boson to other SM particles as well as to itself are measured or constrained in a variety of single and double Higgs boson production processes and decay channels. A selection of these analysis is presented in this talk, as well as the most recent combination results of both single and double Higgs boson measurements.
Combinations of measurements play an important role in high-energy physics: they allow more precise determinations of quantities measured in complementary analyses, and yield new results that can only be obtained by using constraints from multiple sources. These combinations requires a careful statistical treatment. We review the methods and tools used in ATLAS for the combination targeting measurements of SM quantities or searches for new physics. We highlight in particular the methods used in the recent combination of measurements of the Higgs boson production and decay rates and the constraints on the Higgs boson coupling parameters.
Comprehensive understanding of medium-induced radiative energy loss is of a paramount importance in describing observed jet quenching in heavy-ion collisions. In this work, we calculate the medium-modified gluon splitting rates for different profiles of the expanding partonic medium, namely profiles for static, exponential, and Bjorken expanding medium. In the presented study, the Baier-Dokshitzer-Mueller-Peigne-Schiff-Zakharov (BDMPSZ) formalism is used for multiple soft scatterings with a time-dependent transport coefficient for characterizing the expanding medium. The medium-evolved gluon spectra are systematically calculated using the kinetic rate equation for all the medium profiles and a study of the distinctive features at low and high momentum fractions of radiated gluons are provided. Finally, we provide a calculation of the jet $R_{AA}$ which quantifies a sensitivity of the inclusive jet suppression on the way how the medium expands. Comparisons of predicted jet $R_{AA}$ with experimental data from the LHC are also provided.
Open-charmed mesons are unique tools to study the properties of the Quark-Gluon Plasma (QGP) formed in ultra-relativistic nucleus-nucleus collisions. Charm quarks, due to their large mass, are produced in hard partonic scattering processes in the initial stages of the collision. Therefore, they experience all the phases of the QGP evolution propagating through the medium and interacting with its constituents.
The measurement of $\rm D$-meson nuclear modification factor $R_{\rm AA}$, defined as the ratio of the measured yield in nucleus-nucleus collisions to the one in proton-proton interactions scaled by the average number of binary nucleon-nucleon collisions, provides information on the interactions of charm quarks with the medium, in particular on their energy loss. The study of $\rm D$-meson elliptic flow, the second-harmonic coefficient of the Fourier decomposition of the particle momentum-azimuthal distribution with respect to the reaction plane, at low transverse momentum $p_{\rm T}$ can give insight into the participation of charm quarks in the collective expansion of the system and their possible thermalization in the medium. At high $p_{\rm T}$ it allows us to assess the path-length dependence of parton energy loss. These two observables can also shed light on possible modifications of charm-quark hadronization in the medium. In fact, the comparison of the yields of $\rm D$-meson species with and without strange-quark content permits us to study the role of the recombination mechanism for charm quarks.
In this talk, the latest results on the $p_{\rm T}$-differential $R_{\rm AA}$ and flow of $\rm D^0$, $\rm D^+$, $\rm D^{*+}$ and $\rm D_s^+$ mesons measured at mid-rapidity in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV obtained by the ALICE Collaboration will be presented for different centrality classes. The measurements exploit the large data sample collected with ALICE at the end of 2018 and also improved analysis methods based on machine learning techniques. The comparison of the results with model predictions will be discussed as well.
Over a decade, the Relativistic Heavy Ion Collider (RHIC) has provided unique data for the research of proton spin, thanks to its capability of polarized proton – proton (p + p) and polarized proton – ion (p + A) collisions. As a part of RHIC and its spin program, the PHENIX experiment has explored many interesting and unique probes for the better understanding of the proton spin. In this talk, the overview of the PHENIX Spin Program will be presented, concentrating on recent RHIC runs from 2012-2015, for various collision energies, spin orientations (longitudinal or transverse), and collision systems.
The $p_T$ spectrum of direct photons, measured at small $p_T$ in $AA$ collisions,
considerably exceeds the expectations, based on the NLO perturbative calculations. The latter miss the illuminating effect of parton density increase at low $x$ due to the mutual enhancement of the saturation scales in both nuclei.
This effect can be naturally implemented within the dipole formalism, which allows performing calculation even at small $p_T$, that is not reachable with perturbative calculations.
We observe a significant enhancement of the direct photon yield,
apart from the usual Cronin effect in the nuclear modification factor, $R_{AA}$.
$\Lambda$ and $\bar{\Lambda}$ polarization in heavy-ion collisions at BES RHIC energies is studied within the microscopic transport model UrQMD. We trace the formation and space-time evolution of vorticity and helicity patterns in details. This study demands a complex analysis of the fireball conditions including time slices, extraction of temperature and baryo- and strangeness chemical potentials, as well as freeze-out conditions of both hyperons. Rapidity and transverse momentum dependence of the polarization are obtained. We show that difference in global polarization of $\Lambda$ and $\bar{\Lambda}$ at c.m. energies below 10 GeV can be explained by different space-time freeze-out conditions of two hyperons. Comparison with the STAR results shows a fair agreement between the model and the data.
Understanding short-range correlations between pairs of nucleons in the nucleus (SRC) is an important nuclear physics topic that can address longstanding mysteries in nuclear physics such as the behavior of dense nuclear systems and the modification of parton distributions. As a collider and with a large acceptance detector, the EIC has unique capabilities that are complementary to previous SRC studies, most notably the ability to more fully reconstruct the final state. tMaking use of the BeAGLE (Benchmark eA Generator for LEptoproduction) simulation code as well as recent advances in SRC phenomenological parameterizations, we are exploring this potential and determine requirements for beam energies and detectors. In my talk, I will present our current status on simulations for tagged SRCs at an EIC.
ATLAS results on BSM searches in the Higgs sector
Long-lived particles are a powerful tool to search for many models of beyond the Standard Model physics. These striking signatures are explored with the ATLAS detector using 13 TeV pp data, covering displaced decays anywhere from the inner detector to the muon spectrometer. The recent results and HL-LHC prospects will be presented.
Measurements of the top quark mass using the ATLAS detector at the LHC
The measurement of Higgs boson production in association with a ttbar pair is essential to understand the top-quark couplings to the Higgs boson. This talk presents the analyses using Higgs boson decays to bbbar pairs, to multi-lepton final states (WW, ZZ, tau tau) and to a pair of photons, using pp collision data collected at 13 TeV.
The CMS Electromagnetic Calorimeter (ECAL), is a high granularity lead tungstate crystal calorimeter operating at the CERN LHC. The original design placed a premium on excellent energy resolution. Excellent energy resolution and efficient identification for photons are essential to reconstruct the Higgs boson in the H->gg decay channel, for measurements of the self-coupling of Higgs bosons and other related parameters.
The ECAL performance has been crucial in the discovery and subsequent characterisation of the Higgs boson. The original ECAL design considerations, and the actual experimental energy reconstruction and calibration precision will be reviewed.
The improvements to the energy reconstruction and energy calibration algorithms for LHC Run II are described. These are required to maintain the stability of the ECAL energy scale and resolution for the higher LHC luminosities that have been experienced compared to Run I. The precision measurement of the Higgs decay modes is central to the HL-LHC physics program. In addition, the search for di-Higgs production is important to understand the details of the vacuum potential. The crystals in the barrel region will be retained for HL-LHC. The decrease of operating temperature and upgrades to the readout electronics that are needed to maintain the required performance of the barrel region from 2026 onwards will be described.
These upgrades will ensure that radiation-induced noise increases will not dominate the energy resolution for photons from Higgs boson decays, and will preserve the ability of CMS to trigger efficiently on these signals. They will also permit precision time measurements (30 ps rms error on the arrival time of photons from Higgs boson decays) which will improve the determination of the location of the production vertex for di-photon events. Time measurement performance of the new readout electronics has been characterized in beam tests.
The predicted electron and photon energy resolution and identification efficiencies expected for HL-LHC will be described, and the performance relevant to a number of key Higgs decay channels will be presented.
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). In particular, a new timing layer with hermetic coverage up to a pseudo-rapidity of |η|=3 will measure minimum ionizing particles (MIPs) with a time resolution of ~30ps. This MIP Timing Detector (MTD) will consist of a central barrel region based on LYSO:Ce crystals read out with SiPMs and two end-caps instrumented with radiation-tolerant low gain avalanche detectors. The precision time information from the MTD will reduce the effects of the high levels of pile-up expected at the HL-LHC and will bring 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 interaction vertices within the same bunch crossing to recover the track purity of vertices in current LHC conditions. 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. We present motivations for precision timing at the HL-LHC and overview the MTD design, while also highlighting specific physics studies benefiting from the improved timing information.
The p$-$p collisions at high multiplicity at LHC show small scale
collective effects similar to that observed in heavy ion collisions
such as enhanced production of strange and multi-strange hadrons, long range azimuthal correlations, etc.
The observation of strangeness enhancement in p$-$p collisions at $\sqrt{s}$ = 7 TeV and 13 TeV as measured by ALICE experimentis explored using Pythia8 event generator within the framework of microscopic rope hadronization model which assumes the formation of ropes due to overlapping of strings in high multiplicity environment.
The transverse momentum ($p_{T}$) spectra shape and its hardening with
multiplicity is well described by the model. The mechanism of
formation of ropes with QCD-based color reconnections also described
the observed experimental strangeness enhancement for higher multiplicity classes in p$-$p collisions at $\sqrt{s}$ = 7 TeV and 13 TeV. The enhancement with multiplicity is further investigated by studying the mean $p_{T}$ ($
resonance produciton for p$-$p collisions at 7 TeV and 13 TeV
We study a system consisting of a non-Abelian $SU(2)$ Proca field interacting with nonlinear scalar (Higgs) and spinor fields. For such a system, it is shown that particle-like solutions with finite energy do exist. It is demonstrated that the solutions depend on three free parameters of the system, including the central value of the scalar field $\phi_0$. For some fixed values of $\phi _0$, we find energy spectra of the solutions. It is shown that for each of the cases under consideration there is a minimum value of the energy $\Delta=\Delta(\phi_0)$ (the mass gap $\Delta(\phi_0)$ for a fixed value of $\phi_0$). The behavior of the function $\Delta(\phi_0)$ is studied for some range of $\phi_0$.
We show that the energy spectrum has a minimum, at least for some values of $\phi_0$, and we argue that this will also take place for any value of $\phi_0$ lying in the range $0< \phi_0 <\infty$. The behaviour of this minimum as $\phi_0 \rightarrow \infty$ is of great interest: if in this limit the minimum is nonzero, one can say that there is a mass gap $\Delta \neq 0$ in non-Abelian Proca-Dirac-Higgs theory.
If such a mass gap does exist, this would be of great significance. The reason is that in quantum field theory there is a problem to prove the existence
of a mass gap in quantum chromodynamics. This problem is highly nontrivial and any examples of its existence (even within a classical theory)
would be very useful for an understanding of the nature of existence of the mass gap.
If there is a mass gap in the theory we are investigating, it is possible that this is due to the fact that non-Abelian Proca-Dirac-Higgs theory is some approximation for nonperturbative quantization in QCD. In this case, it can be assumed that the Proca field describes a $SU(2)$ subgroup of $SU(3)$, the Higgs scalar field describes sea gluons and the Dirac nonlinear field describes sea quarks.
Thus, the purpose of the investigation is to (i) obtain particle-like solutions within a theory with a non-Abelian $SU(2)$ Proca field plus a Higgs scalar field plus a nonlinear Dirac field; (ii) study energy spectra of these solutions; and (iii) search for a minimum of the spectrum (a mass gap).
The talk is based on Phys.Rev. D99 (2019) no.7, 076009
The laws of nature are expected to remain the same under mirror reflection. Parity symmetry is known to be respected by classical gravitation, electromagnetism, and the strong interaction but discovery indicates that the weak interaction acts only on left-handed particles and right-handed antiparticles. It has the maximal violation of parity and chirality. So far, there is no explanation for these phenomena. In our previous work, we propose a new baryogenesis scheme based on string theory to explain the observed matter dominance in our universe. In string theory, there exist two separate and relatively independent sectors corresponding to left moving or right moving, holomorphic or antiholomorphic vibrations in the internal spacetime, the worldsheet. Our observable spacetime, elementary particles, and fundamental forces such as gravity and gauge interactions are projections from the internal spacetime. We suggest that if we propose that the observed universe chooses to stay in one of the sectors in the internal spacetime, this may bring the observed asymmetry between matter and anti-matter. In this work, we propose and show that further development of this new string theory based baryogenesis mechanism may also explain why chiral (C) and parity (P) symmentry is broken in weak interaction but preserved in other gauge interactions.
In a previous effort we have created a framework that explains why topological structures naturally arise within a scientific theory; namely, they capture the requirements of experimental verification. This is particularly interesting because topological structures are at the foundation of geometrical structures, which play a fundamental role within modern mathematical physics. In this talk we will show a set of necessary and sufficient conditions under which those topological structures lead to real quantities and manifolds, which are a typical requirement for geometry. These conditions will provide a physically meaningful procedure that is the physical counter-part of the use of Dedekind cuts in mathematics. We then show that those conditions are unlikely to be met at Planck scale, leading to a breakdown of the concept of ordering. This would indicate that the mathematical structures required to describe space-time at that scale, while still topological, may not be geometrical.
This is a minireview devoted to the problem of vacuum dynamics in $3d$
supersymmetric Yang-Mills-Chern-Simons theories with and without extra
matter multiplets. Performing an explicit analysis of the effective Born-Oppenheimer Hamiltonian in a small spatial box, we calculate the number of vacuum states (the Witten index) for these theories and analyze their structure.
The method of this study is similar to the method developped by Witten for 4-dimensional supersymmetric gauge theories, but 3-dimensional theories turn out to be more complicated and their dynamics involves interesting non-trivialities. In particular: (i) the tree-level effective Hamiltonian is not just a free Laplacian, but involves an extra homogeneous magnetic field, (ii) it is not enough to analyze the effecive Hamiltonian to the leading BO order, but one-loop corrections should also be taken into account.
The oscillations of neutrinos has provided evidence for their nonzero masses and mixing, and also the presence of physics beyond the Standard Model. In this talk I will give a brief outline of neutrino oscillations and present the current status. I will also discuss the next generation of long baseline neutrino experiments.
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 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 200\,$\mbox{MeV/c}^2$. 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 CERN SPS Committee recommended in 2016 that the experiment and the beam dump facility studies proceed to a Comprehensive Design Study phase. These studies have resulted in a mature proposal submitted to the European Strategy for Particle Physics Update.
The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratory 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, contributing to constraint the allowed parameters to a narrow region around $\Delta m^2 \sim$ eV$^2$, where all
the experimental results can be coherently accomodated at $90 \%$ CL. 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 sterile neutrino within the Short Baseline Neutrino (SBN) program, devoted to clarify in a definitive way the open questions of the presently observed neutrino anomalies. The contribution will address ICARUS achievements and plans for the sterile neutrino search at Fermilab.
The knowledge of initial flux, energy and flavor of current neutrino beams is currently the main limitation for a precise measurement of neutrino cross sections. The ENUBET ERC project (2016-2021) is studying a facility based on a narrow band neutrino beam capable of constraining the neutrino fluxes normalization through the monitoring of the associated charged leptons in an instrumented decay tunnel. Since March 2019, ENUBET is also a CERN Neutrino Platform project (NP06/ENUBET) developed in collaboration with CERN A&T and CERN-EN. In ENUBET, the identification of large-angle positrons from $K_{e3}$ decays at single particle level can potentially reduce the $\nu_e$ flux uncertainty at the level of 1%. This setup would allow for an unprecedented measurement of the $\nu_e$ cross section at the GeV scale. Such an experimental input would be highly beneficial to reduce the budget of systematic uncertainties in the next long baseline oscillation projects (i.e HyperK-DUNE). Furthermore, in narrow-band beams, 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.
This contribution will present the final design of the ENUBET demonstrator, which has been selected on April 2019 on the basis of the results of the 2016-2018 testbeams. It will also discuss advances in the design and simulation of the hadronic beam line. Special emphasis will be given to a static focusing system of secondary mesons that, unlike the other studied horn-based solution, can be coupled to a slow extraction proton scheme. The consequent reduction of particle rates and pile-up effects makes the determination of the $\nu_{\mu}$ flux through a direct monitoring of muons after the hadron dump viable, and paves the way to a 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. We will also present the performance of positron tagger prototypes tested at CERN beamlines, a full simulation of the positron reconstruction chain and the expected physics reach of ENUBET.
References:
F. Acerbi et al., Irradiation and performance of RGB-HD Silicon Photomultipliers for calorimetric applications, JINST 14 (2019) P02029.
F. Acerbi et al., A high precision neutrino beam for a new generation of short baseline experiments, arXiv:1901.04768.
F. Acerbi et al., The ENUBET project, CERN-SPSC-2018 / SPSC-I-248, 31/10/2018.
M. Pozzato et al., Status of the ENUBET project, J.Phys.Conf.Ser. 1056 (2018) no.1, 012047.
F. Pupilli et al., ENUBET: High Precision Neutrino Flux Measurements in Conventional Neutrino Beams, PoS NuFact2017 (2018) 087.
G. Ballerini et al, Testbeam performance of a shashlik calorimeter with fine-grained longitudinal segmentation, JINST 13 (2018) P01028.
A. Berra et al., Shashlik Calorimeters With Embedded SiPMs for Longitudinal Segmentation, IEEE Trans. Nucl. Sci. 64 (2017) no.4, 1056-1061.
A. Longhin et al., High precision measurements of neutrino fluxes with ENUBET, PoS NEUTEL2017 (2018) 050.
A. Berra et al., Longitudinally segmented shashlik calorimeters with SiPM readout, Nucl. Instrum. Meth. A845 (2017) 511-514.
F. Terranova et al., The ENUBET project: high precision neutrino flux measurements in conventional neutrino beams, PoS (EPS-HEP2017) 138.
A. Berra et al. Enabling precise measurements of flux in accelerator neutrino beams: the ENUBET project CERN-SPSC-2016-036 / SPSC-EOI-014, 05/10/2016.
A. Meregaglia et al., ENUBET: Enhanced NeUtrino BEams from kaon Tagging, JINST 11 (2016) no.12, C12040.
The International Particle Physics Outreach Group (IPPOG) is a network of scientists, science educators and communication specialists engaged in informal science education and outreach for particle physics. The primary goal of the IPPOG members is the development and collection of material and the sharing of best practices in outreach; also increasing awareness about the importance of outreach within our own scientific community. The flagship activity of IPPOG is the International Particle Physics Masterclasses programme; it also supports International Muon Week and International Cosmic Day, as well as a whole spectrum of activities such as public talks, festivals, exhibitions, teacher training, student competitions, and open days at local institutions. The aim of all these activities, targeting a public with a variety of backgrounds, is to improve worldwide understanding and support of science, to inspire and motivate the young generation and to gain the trust and support of decision-makers.
TBA
TBA
The Physics Laboratory of the Hellenic Open University has constructed a small scale and low cost air shower detector suitable for operation inside the classroom or school laboratory (microCosmics detector). In this work we present some of the educational activities foreseen with the microCosmics air shower detector as well as the planning for the operation of the 1st array of extensive air shower detectors in Greece. The array will consist of 5 autonomous stations deployed at high school buildings in the city of Patras in western Greece and it will be in operation from the autumn of 2019.
The HiSPARC experiment carries out cosmic ray research with the help of high school students. Universities, scientific institutes and predominantly high schools collaborate by hosting their own cosmic ray detection station. Our outreach goal is to bring modern physics into the classroom. In this talk I will show how we promote and enable the use of Jupyter Notebooks in high schools. The notebooks are used during lectures and also for individual student projects. With Jupyter students learn how to program and how to process the (big) data of their own cosmic ray station.
If science outreach is about connecting with new audiences, music remains a uniquely accessible form of outreach. However, physics music needn’t be limited to campy parodies. A new project for creating music that is accessible at multiple technical levels will be presented. Using a form of 2D wavetable synthesis, a new form of electronic music uses stereo audio signals, mapped onto an oscilloscope’s X-Y mode, to create 3D images of LHC experiments from the music itself. Both composed and improvised forms of this project are able to reach electronics communities, fans of electronic music, and musicians; and physics departments can revive analog oscilloscopes from storage to create an essentially free outreach display.
The ALICE collaboration recognises the necessity and importance of science communication and outreach and uses a multitude of methods to reach out to the public. A non-exhaustive list of activities includes particle physics masterclasses for students and teachers; visits of the experiment, both of the underground installations during LHC stops and of the new ALICE exhibition; virtual visits which allow ALICE members to reach remote audiences; also participation in events such as Researchers’ Night and CERN Open Days. The many communication tools available in our digital era, such as social media and online newsletters, allow to target groups of different ages and interests. All the above also encourage more members of our own community to engage in outreach, which is in itself is an enriching activity.
TBA
TBA
TBA
Round Table on Future of Fundamental Physics with John Womersley, Jorgen d’Hondt, Katsunobu Oide, Akira Yamamoto, Victor Matveev, Meng Wang, Andrea Latina, Michael Koratzinos
The excursion will visit the Palace of Knossos, center of the Minoan civilization (3650-1450 BCE), considered Europe's oldest city, where the legendary King Minos has reigned, with the Labyrinth of Minotaurus in which human sacrifices were made. His mother Europi (Ευρωπη) broad to Crete by Zeus, gave her name to the continent of Europe. The excursion will visit also the Museum of Herakleion, one of the richest Musea in Greece.
See the following link for more information:
https://indico.cern.ch/event/754973/attachments/1709872/3125298/Excursion_to_Knosses.pdf
The excursion will visit famous historical Monasteries in the mountains of Crete, including the celebrated Holy Monastery of Chrysopigi(16th century) with its rare Exhibition of old paintings.
There will be 2 buses at 6 a.m. and 8 a.m. In OAC there will be
coffee and cookies arranged from 5:00 till 7:30.
See the following link for more information:
https://indico.cern.ch/event/754973/attachments/1709872/3125306/Excursion_to_Monasteries.pdf
The Fallassarna beach, one of the most famous and purest beaches of Crete.
See the following link for more information:
https://indico.cern.ch/event/754973/attachments/1709872/3125303/Excursion_to_Falassarna.pdf
Selected recent results from the ATLAS experiment will be hightlighted in the talk. Emphasis will be given to recent progresses in the measurements of the Higgs properties, Standard Model processes as well as searches for new physics beyond the Standard Model.
In this talk we will highlight recent results from LHCb with a focus on measurements of CP violation in b and c decays and measurements testing Lepton Flavor Universality at LHCb .
The most recent results on CP violation in the decay, mixing and interference of both b and c hadrons obtained by the LHCb Collaboration with Run I and years 2015-2016 of Run II are reviewed. In particular world best constraints and world first measurements are provided for CKM elements, unitarity angles and charm parameters.
The concept of lepton universality, where the muon and tau particles are simply heavier copies of the electron, is a key prediction in the Standard Model (SM). In models beyond the SM, lepton universality can be naturally violated with new physics particles that couple preferentially to the second and third generation leptons. Over the last few years, several hints of lepton universality violation have been seen in both b->c and b->s semileptonic beauty decays. This presentation will review these anomalies and give an outlook for the near future. Other probes of NP in highly suppressed b-hadron decays will also be discussed.
In recent years, the ALICE experiment at the CERN LHC has published a lot of exciting
measurements aiming to characterise the properties of the Quark Gluon Plasma (QGP),
a state of matter formed in high energy collisions at extremely high temperature
and/or energy density.
ALICE has collected precision data at different energies for proton-proton (pp),
proton-lead (p-Pb), lead-lead (Pb-Pb) and xenon-xenon (Xe-Xe) collisions.
In this presentation, we will summarise the results that best represent a step forward
towards the understanding of the QGP formed at the LHC.
Emphasis will be given to recent results from the LHC run 2, spanning from the soft
sector (bulk particle production and correlations) to hard probes (charmed hadrons
and jets), and to signatures of possible collective effects in high multiplicity pp
and p-Pb collisions.
It is well known that in the absence of interactions the quantum Hall (QHE) conductivity in the presence of constant magnetic field is expressed through the topological TKNN invariant. The same invariant is responsible for the intrinsic anomalous quantum Hall effect (AQHE), which, in addition, may be represented as one in momentum space composed of the two point Green function. We propose the generalization of this expression to the QHE in the presence of non-uniform magnetic field. The proposed expression is the topological invariant in phase space composed of the Wigner transformation of the two-point Green function. It is applicable to a wide range of non-uniform tight-binding models, including the interacting ones.
The Large Hadron Collider (LHC) has been successfully delivering proton-proton collision data at the unprecedented center of mass energy of 13 TeV.
An upgrade is planned to increase the instantaneous luminosity delivered
by LHC in what is called HL-LHC, aiming to deliver a total of about 3000/fb of data to the ATLAS detector. To cope with the expected data-taking conditions ATLAS is planning major upgrades of the detector.
In this contribution we present an overview of the physics reach expected for a wide range of measurements and searches at the HL-LHC for the ATLAS experiment, including Higgs coupling, di-Higgs boson production sensitivity, Vector Boson Scattering prospects as well as discovery potential for electroweak SUSY and other exotic benchmark scenarios.
Such studies formed the basis of the ATLAS Collaboration input to the recent HL/HE-LHC Yellow-Report. An executive summary of this report was then submitted as input to the European Strategy process.
The recent realization that highest energy p-p data can be simply explained in terms of a black disc with a constant `edge' is elucidated. The application to nuclei has significant implications for the understanding of cosmic ray showers. Another interesting point concerns understanding the coefficient of the Froissart bound in the limit of zero pion mass.
J-PARC Heavy Ion project(J-PARC-HI) is a future fixed target experiment to study the properties of the dense matter created by the heavy ion collisions with 1-12 AGeV/c at J-PARC. The search for the QCD phase boundary and the critical end point is one of the important topics to understand the nature of QCD phase transition. It is also of interest to study the equation of state of the dense matter at J-PARC, where the density of the matter is similar with that of neutron star and neutron star merger.
For this purpose, the high intensity beam and the precision detector with high speed DAQ is necessary. J-PARC will be upgraded to produce the world highest heavy ion beam with adding a new compact heavy-ion linac and a booster ring, and utilizing the current RCS and MR synchrotrons. We will construct the multi-purpose spectrometer with large acceptance to measure dileptons, photons and hadrons, and their correlations and fluctuations.
In this presentation, we will report the current status of the project,
the design of the detector configuration, and detector R&D status.
The main goal of the ALICE experiment is to study the physics of strongly interacting matter under extremely high temperature and energy density conditions to investigate the properties of the Quark-Gluon plasma (QGP). The enhanced production of strange hadrons with respect to non-strange particles was historically considered as one of the signatures of QGP formation during the evolution of the system created in heavy-ion collisions. The excellent tracking and particle identification capabilities of the ALICE experiment allow the reconstruction of multi-strange baryons via their weak decay channels over a large range of transverse momentum. In this talk the yields and the relative production rates of strange and multi-strange particles normalized to pions measured in pp, p-Pb, Pb-Pb and Xe-Xe collisions will be presented as a function of particle multiplicity. The strangeness production dependence on the collision energy will also be shown. Results will be compared to QCD-inspired and statistical hadronization model predictions.
.
According to the widely accepted picture in the heavy-ion community, the observed non-uniform distribution of particles in the final momentum space is a manifestation of the non-uniformities in the initial energy density and the collective evolution of interacting matter. Furthermore, the initial energy density profile fluctuates from one event to the other, and this event-by-event fluctuation leads to a rich statistical structure of flow harmonic fluctuations in the final stage. Up to the present day, only a tiny corner of this statistical structure has been explored. The cumulants of individual flow harmonics have been studied extensively, and only recently the correlations of two different flow harmonics, via the new flow observables called Symmetric Cumulants (SC), have been investigated. Moreover, the fluctuations are mostly considered to be Gaussian while recent studies indicate that the skewness and kurtosis of the fluctuations are nonvanishing and their connection to the cumulants of individual flow harmonics is stablished.
In this talk, we first show how we can go one step further in understanding the flow fluctuations by introducing generalized SCs, the genuine correlation between more than two different flow harmonics. Generalized SCs provide new and independent information for Quark-Gluon Plasma properties, which is inaccessible to other flow observables used by now. Then by employing the iEBE-VISHNU model, we demonstrate the first predictions for the generalized SCs at LHC energies. We also show that they are robust against systematics biases from nonflow effects by exploiting the HIJING event generator. Additionally, we will show how one can connect the non-Gaussianity to the cumulants of the individual flow harmonics systematically. We stress that in interpreting the cumulants as genuine anisotropic flow the fluctuations have to be considered as a Gaussian distribution. For the case the fluctuations are manifestly non-Gaussian, we present a new estimator for the genuine anisotropic flow in terms of cumulants.
Based on:
[1] C. Mordasini, A. Bilandzic, D. Karakoç, S. F. Taghavi, "Higher order Symmetric Cumulants", [ arXiv:1901.06968v2 [nucl-ex]]
[2] H. Mehrabpour and S. F. Taghavi, "Non-Bessel–Gaussianity and flow harmonic fine-splitting", Eur. Phys. J. C 79, no. 1, 88 (2019) [arXiv:1805.04695 [nucl-th]]
Azimuthal anisotropy correlations between different Fourier harmonics, $v_2$, $v_3$, and $v_4$ measured with two-particle correlations in simulated PbPb collisions at $\sqrt{s_{_{\mathrm{NN}}}}=2.76~$TeV, generated with HYDJET++ and AMPT generator, are presented. The results are compared with data from the ATLAS experiment. Both models are in good agreement with data for $v_2$-$v_3$ correlation. For $v_2$-$v_4$ and $v_3$-$v_4$ correlations AMPT model is still in good agreement with experimental observations, while HYDJET++ gives stronger slopes with respect to the ones observed by the ATLAS collaboration. Further, initial-state fluctuations from HYDJET++ model are measured in PbPb collisions at $\sqrt{s_{_{\mathrm{NN}}}}=5.02~$TeV by comparing $v_2$ results obtained with different Q-cumulant order, $v_2\{2\},v_2\{4\},v_2\{6\},$ and $v_2\{8\}$. The model calculation shows good qualitative and rather good quantitative agreement with results reported by the CMS experiment.
Results of the study of the confinement - deconfinement transition in lattice SU(2) QCD at large quark density and zero temperature are presented. At $\mu_q$ about 1000 MeV we observe vanishing of the string tension indicating confinement - deconfinement transition. We further present results of the deconfinement phase properties study.
We discuss the tight-binding models of solid state physics with the $Z_2$ sublattice symmetry in the presence of elastic deformations, and their important particular case - the tight binding model of graphene. In order to describe the dynamics of electronic quasiparticles we explore Wigner-Weyl formalism. It allows to calculate the two-point Green function in the presence of both slowly varying external electromagnetic fields and the inhomogeneous modification of the hopping parameters resulted from the elastic deformations. The developed formalism allows us to consider the influence of elastic deformations and the variations of magnetic field on the quantum Hall effect.
We develop Wigner - Weyl formalism for the lattice models. For the definiteness we consider Wilson fermions in the presence of U(1) gauge field. The given technique reduces calculation of the two point fermionic Green function to solution of the Groenewold equation. It relates Wigner transformation of the Green function with the Weyl symbol Q_W of Wilson Dirac operator. We derive the simple expression for Q_W in the presence of varying external U(1) gauge field. Next, we solve the Groenewold equation to all orders in powers of the derivatives of Q_W . Thus the given technique allows to calculate the fermion propagator in the lattice model with Wilson fermions in the presence of arbitrary background electromagnetic field. The generalization of this method to the other lattice models is straightforward.
We show that the properties of the layered phase of anisotropic gauge theories provide insights into the properties of topological insulators and provide useful computational tools for their quantitative description.
The Chiral Magnetic Effect (CME) is of exclusive interest since it allows probing topological properties of QCD and is a possible macroscopic manifestation of the chiral anomaly. The CME was recently observed experimentally in Dirac semimetals, but for QCD the effect has not yet been confirmed.
Within this work the CME in Dirac semimetals and QCD was studied within lattice simulation. For QCD we use stout smeared 2 + 1 staggered fermions at physical pion and strange quark mass and observe the rapid growth of conductivity $\sigma_{\parallel}$ in the direction of external magnetic field $B$, which is in agreement with the CME predictions.
In this talk I propose to discuss new insights as to the interconnection of initially apparently independent and distinct types of gauges:
a) Charge-like gauges, obtained from local current-densities, with space-integrals of dimension charge, i.e. dimensionless.
b) gauges of orientation, reducible to a dimensionless metric tensor g_{mu nu} (x) and associated with Riemann-tensor combinations of dimension mass-square or equivalently inverse length, using rational units : hbar = c = 1 .
The causality amd locality structure of the orientation gauges [of type b)]
is serving as fundamental fields, whereas charge-like gauges [a)] are to be eliminated.
TBA
The ATLAS experiment at the Large Hadron Collider utilises a trigger system consisting of a first level hardware trigger and a higher level software trigger. The Level-1 muon trigger system selects muon candidates with six transverse momentum thresholds and associate them with a correct LHC bunch crossing. The Level-1 Muon Barrel Trigger uses Resistive Plate Chambers (RPC) detectors to generate trigger signals for selecting muon candidates within the pseudorapidity range of up to 1.05. The RPC detectors are arranged in three concentric double layers and consist of 3600 gas volumes, with a total surface of more than 4000 square meters, that operate in a toroidal magnetic field. This contribution will discuss the performance of the RPC detector system and of the Level-1 Muon Barrel trigger during the 2018 data taking period. Measurements of RPC detector response obtained using muon candidates produced in LHC collisions will be presented. Trigger performance and efficiency measurements that are obtained using Z boson decays to a muon pair will be also discussed. Finally, studies of the RPC detector response at different high voltage and threshold settings will be discussed, in the context of expected detector response after the High Luminosity LHC upgrades
The upcoming luminosity upgrade of the LHC will impose new requirements for the detector installations. To perform under these conditions the Micromegas (MM) technology was selected to be adopted in the New Small Wheel (NSW) upgrade, dedicated to precision tracking. A large surface of the forward regions of the Muon Spectrometer will be equipped with 8 layers of MM modules forming a total active area of 1200 m2. The NSW is planned to be installed in the forward region of 1.3 < |η| < 2.7 of ATLAS. The NSW will have to operate in a high background radiation region, while reconstructing muon tracks as well as furnishing information for the Level-1 trigger. The project requires fully efficient MM chambers with spatial resolution down to 100 μm, a rate capability up to about 15 kHz/cm2 and operation in a moderate (highly inhomogeneous) magnetic field up to B=0.3 T. The required tracking is linked to the intrinsic spatial resolution in combination with the demanding mechanical accuracy.
An overview of the design, construction and QA/QC procedures followed at the Aristotle University of Thessaloniki for the Micromegas LM2 Drift panels production will be presented.
The model independent results on the investigation of the dark matter annual modulation signature by DAMA/LIBRA-phase2 will be outlined, and their implications on several Dark Matter scenarios will be presented. Thanks to the increased exposure and to the lower software energy threshold, corollary model-dependent analyses permit to significantly restrict the allowed regions for the parameters spaces of various dark matter candidates and astrophysical, particle and nuclear physics scenarios.
The DarkSide program aims at detecting weakly interacting particle dark matter using dual-phase Liquid Argon Time Projection Chambers (LAr TPC) of increasing sensitivity. One of the distinctive features of the program is the use of underground argon with significantly lower 39Ar when compared with atmospheric argon.
The first detector of the program, DarkSide-50 (DS-50) is running at LNGS since 2013. It is the first detector of its kind with a large (30 tonnes), liquid scintillator neutron veto and water Cherenkov (1,000 tonnes) muon veto concentrically enveloping the dark matter target. An initial 1,422 kg*day exposure run with atmospheric argon yielded a null result of the dark matter search and zero background from radioactive sources. Operations with underground argon started in March 2015, and results from background-free 500-day exposure have been recently released. Argon-39 suppression in underground argon is proven to be more than 1000-fold, making much larger detectors free of instrumental background possible. Recently, DS-50 has also yielded exquisite sensitivity for low and very-low mass dark matter particles, below 10 GeV/c2.
I will review the DS-50 results and present the future of the DarkSide program, DS-20k. DS-20k is multi-tens of tons detector designed for a background-free exposure of 100 tonne-years, with a projected sensitivity to WIMP-nucleon cross section of better than 10-47 cm2 for WIMPs of mass 1 TeV/c2, a mass scale of special interest because above the reach of the LHC. Details of the DS-20k detector and R&D towards its finalization will be presented in the global context of direct dark matter searches.
The Sodium-iodide with Active Background REjection (SABRE) experiment is designed to search for the annual modulation of the dark matter interaction rate with NaI(Tl) crystals. The experiment will also be able to perform a conclusive and model-independent test of the DAMA/LIBRA annual modulation signal. This signal is compatible with the expected dark matter galactic distribution, but it is in contrast with observations from different-target dark matter experiments under the standard WIMP hypothesis.
SABRE will perform a high sensitivity dark matter search using NaI(Tl) crystals with unprecedented radio-purity operated inside a liquid scintillator veto for active background rejection. The properties of such crystals make the experiment also ideal for the detection of faint x-ray emissions from charged particles, which are a by-product of certain quantum mechanics theories. The most popular of such theories are the Continuous Spontaneous Localization (CSL) and the Diosi-Penrose (DP) models, which address foundational quantum mechanics problems like: “why the wave function of a quantum system collapses to a single state as a consequence of the measurement of one of its observables?” and “how classical macroscopic behaviours emerge from the quantum world?”.
The first phase of the experiment, the SABRE Proof-of-Principle (PoP), is underway. A single 3.5 kg crystal detector is hosted in a two-ton liquid scintillator veto system at the Laboratori Nazionali del Gran Sasso. The goal of this phase is to measure the crystal background, test the active background rejection system.
This talk will illustrate the characteristics of the SABRE experiment and its expected sensitivity at testing both dark matter theories and quantum mechanics models. The status of the SABRE PoP and any preliminary result will also be presented.
The features of the NA62 experiment at the CERN SPS – high-intensity setup, trigger-system flexibility, high-frequency tracking of beam particles, redundant particle identification, and ultra-high-efficiency photon vetoes – make NA62 particularly suitable to search for long-lived, weakly-coupled particles within Beyond the Standard Model (BSM) physics, using kaon and pion decays as well as operating the experiment in dump mode.
The NA62 sensitivity for searches of Heavy Neutral Leptons, Dark Photons and Axion-Like Particles are presented, together with prospects for future data taking at the NA62 experiment.
Positronium (Ps), the bound state of an electron and a positron, is one of the best candidates for the first Bose-Einstein condensation (BEC) of antimatter system. Ps-BEC can be regarded as an “antimatter laser”, which has rich potential for applications to both fundamental and applied physics. For example, the gravitational effect on antimatter can be studied by constructing a Mach-Zehnder interferometer of Ps-BEC. Gamma-ray laser can also be realized using annihilation gamma-rays from Ps-BEC.
The challenge to realize Ps-BEC is to create dense (> 10$^{17}$ cm$^{-3}$) and cold (< 10 K) Ps atoms in a short lifetime of Ps (142 ns). To achieve these target values, we proposed the following new scheme. Firstly, dense Ps atoms are formed in small (~ 10$^6$ nm$^3$) pores in a silica (SiO$_2$) target by bombarding focused and bunched positron beams. Then, Ps atoms are rapidly cooled to ~300 K by thermalization caused by collisions with pore walls. Finally, Ps are cooled to less than 10 K by laser cooling which uses 243 nm 1S-2P transitions. Monte Carlo simulation shows that this method can realize Ps-BEC in ~300 ns after Ps formation.
We are currently trying laser cooling of Ps at KEK slow positron facility (SPF). In this presentation, I will show the overall development status and future prospects of our experiment, especially about the following topics: positron fusing system using multi-stage brightness enhancement system, Ps generator/condenser/cooler target material, and special home-made 243 nm pulsed laser system for Ps cooling.
This work is supported by JSPS KAKENHI Grant Numbers JP16H04526, JP17H02820, JP17H06205, JP17J03691, JP18H03855, JP19H01923, MATSUO FOUNDATION, Mitutoyo Association for Science and Technology (MAST), Research Foundation for Opto-Science and Technology, and TIA Kakehashi TK17-046.
A main scientific goal of the $AE\bar{g}IS$ experiment is the direct measurement of the Earth's local gravitational acceleration $g$ on antihydrogen. The weak equivalence principle is a foundation of General Relativity. It has been extensively tested with ordinary matter but very little is known about the gravitational interaction between matter and antimatter. Antihydrogen is produced in $AE\bar{g}IS$ via resonant charge exchange reactions between cold Rydberg-excited positronium and cooled down antiprotons. The achievements towards the development of a pulsed cold antihydrogen source are presented.
Large number of antiprotons, necessary for a significant production rate of antihydrogen, are captured, accumulated, compressed and cooled down over an extended period of time. Positronium (Ps) is formed through $e^+$-Ps conversion in a silica porous target at 10 K temperature in a reflection geometry inside the main apparatus. The so-formed Ps cloud is then laser-excited to Rydberg levels leading to the first Ps laser excitation to the Rydberg levels in a 1T magnetic field and to the detailed characterisation of the Ps source for antihydrogen production.
Several detection techniques are extensively used to monitor antiproton and positron manipulations in the formation process of antihydrogen inside the main apparatus. Positronium detection techniques underwent extensive improvements in sensitivity in 2018. At the same time, major efforts to improve integrate and commission the various detector sensitive to antihydrogen production took place. These include an array of external scintillators and a scintillating fiber based tracking detector. Measurements based on this improved detection system will be presented.
Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. The direct production of electroweak SUSY particles, such as sleptons, charginos, and neutralinos, is a particularly interesting area with connections to dark matter and the naturalness of the Higgs mass. This talk will present results from searches for electroweak SUSY partners using data collected with the ATLAS experiment in Run-2 at the LHC. Several signatures are employed, and the results of the searches interpreted as constraints on a variety of SUSY models.
I will present the latest results on searches for supersymmetry with the CMS detector at the LHC.
ALICE (A Large Ion Collider Experiment) is the CERN LHC experiment optimized for the study of the strongly interacting matter produced in heavy-ion collisions and for the characterization of the quark-gluon plasma (QGP).
ALICE has collected precision data at different energies for pp, p-Pb, Pb-Pb and Xe-Xe collisions: this unique set of data allows us to investigate bulk particle production for very different systems and compare them at similar multiplicities. In particular, light flavour particles, containing only u, d and s valence quarks, are the most copiusly produced and so they play a central role in the characterization of the bulk properties of the QGP, carrying essential information about the produced medium and reaction dynamics.
Part of this information is carried by the inclusive and identified transverse momentum distributions of light charged particles, measured over a wide $p_\mathrm{T}$ range thanks to the excellent tracking and particle-identification capabilities of the ALICE detector.
Such distributions show that at low to intermediate $p_\mathrm{T}$ charged particle production is governed by the collective expansion of the system. The chemical and kinetic freeze-out parameters of the system are extracted via statistical-thermal and combined blast-wave fits to the data in heavy-ion collisions and are compared to results obtained in pp and p-Pb collisions at similar multiplicities. At high $p_\mathrm{T}$, typically above 5 GeV/$c$, a suppression of hadronic production, due to medium effects such as parton energy loss, can be observed. These effects can be investigated by calculating the nuclear modification factor, defined as the ratio between the $p_\mathrm{T}$ spectrum measured in nucleus-nucleus collisions and a reference spectrum in pp collisions scaled by the number of binary nucleon-nucleon collisions.
In this talk, we review the most recent ALICE results on the production of pions, kaons and protons, including transverse momentum spectra, yields, particle ratios, mean transverse momenta and nuclear modification factors, for various centrality/multiplicity classes.
I will speak about new approach to collectivity and thermalization problem
based on the concept of entanglement entropy.
We propose that ordinary semiconductors with large spin-orbit coupling, such as GaAs, can host stable, robust, and tunable topological states in the presence of quantum confinement and superimposed potentials with hexagonal symmetry.
We show that the electronic gaps which support chiral spin edge states can be as large as the electronic bandwidth in the heterostructure miniband.
[1] O. P. Sushkov, A. H. Castro Neto, Phys. Rev. Lett. 110, 186601 (2013).
[2] O. A. Tkachenko, V.A. Tkachenko, I. S. Terekhov, O. P. Sushkov, 2D Materials 2, 014010 (2015).
[3] H. D. Scammell and O. P. Sushkov, Phys. Rev. B 99, 085419 (2019).
In this report we present the results of our studies of confinement/deconinement transition in cold dense quark matter in QCD-like theories. In particular, we are going to study two-color QCD at large baryon density and tree-color QCD at large isospin density. It is known that these theories are free from sign problem what allows us to apply lattice simulation. We found that at sufficiently large baryon density (for two colors) and large isospin density (for three colors) these systems transfer from confinement to deconfinement phase. We also present our results of the study of the properties of these systems in the region of large baryon/isospin densities.
The ATLAS collaboration at LHC has chosen the resistive Micromegas technology, along with the small-strip Thin Gap Chambers (sTGC), for the high luminosity upgrade of the first muon station in the high-rapidity region, the so called New Small Wheel (NSW) project. After the R&D, design and prototyping phase, the first series production Micromegas quadruplets are being constructed at the involved construction sites in France, Germany, Italy, Russia and Greece. At CERN, the final validation and the integration of the modules in Sectors are in progress. These are big steps forward for the installation of the NSW foreseen for the LHC long shutdown in 2019 and 2020. The construction of the four types of large size quadruplets, all having trapezoidal shapes with surface areas between 2 and 3 m2, will be reviewed. The achievement of the requirements for these detectors revealed to be even more challenging than expected, when scaling from the small prototypes to the large dimensions. We will describe the encountered problems, to a large extent common to other micro-pattern gaseous detectors, and the adopted solutions. Final quality assessment and validation results on the achieved mechanical precision, on the High-Voltage stability during operation with and without irradiation will be presented together with the most relevant steps and results of the modules integration into sectors.
ATLAS electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential to record signals for a wide variety of physics: from Standard Model processes to searches for new phenomena in both proton-proton and heavy ion collisions. Main triggers used during Run 2 (2015-2018) for those physics studies were a single-electron trigger with ET threshold around 25 GeV and a diphoton trigger with thresholds at 25 and 35 GeV. Relying on those simple, general-purpose triggers is seen as a more robust trigger strategy, at a cost of slightly higher trigger output rates, than to use a large number of analysis-specific triggers. To cope with ever-increasing luminosity and more challenging pile-up conditions at the LHC, the trigger selections needed to be optimized to control the rates and keep efficiencies high. The ATLAS electron and photon performance during Run-2 data-taking is presented as well as work ongoing to prepare to even higher luminosity of Run 3 (2021-2023).
The architecture of the present ATLAS Muon spectrometer was designed for a luminosity of 10^34 cm-2 s-1 with a security factor of 5 with respect to the simulated background rate, now confirmed by the LHC Run 1 results. Since HL-LHC will have a 5 times higher luminosity and a one order of magnitude bigger background, the demand in terms of performances increases, being the detector operated in a much harsher conditions.
The BI project is one of the LHC Phase-2 approved upgrades, in order to ensure the demands coming from the physics for the next 20 years. It consists in the installation of an entire new layer of Resistive Plate Chamber detectors inside the Inner Barrel of the ATLAS experiment. This will ensure higher redundancy and robustness of the trigger system, almost complete acceptance and an improved momentum selectivity.
The BIS78 upgrade, scheduled for LHC Phase-1, is the pilot project for the BI RPCs installation. It aims at the installation of 10% of the BI RPCs in the transition region between the endcap and the Inner Barrel of ATLAS experiment. This barrel region is the one with the highest background and for this reason is an excellent test bench for the BI upgrade. The BIS78 position will also help in the reduction of the fake muons produced upstream with respect to the cryostats.
The BI RPCs represent a new generation of RPCs, basing their largely improved performances on a new and highly performing Front-End electronics, which is able to detect 10 times smaller signals leading to an increase in rate capability of a factor 10, and on gas gap of 1 mm with 1.2 mm electrodes thickness, granting a time resolution of 350ps and less space occupancy.
The BI project will be illustrated along with the performances of the prototype of this new generation of RPC detectors.
The Hellenic Open University extensive air shower array is a small scale hybrid detection system operating in urban environment with strong human made electromagnetic noise. In this work we present the latest results of the data analysis concerning the estimation of the shower parameters using the RF system. In a recent layout of the array, 4 RF antennas were operating receiving a common trigger of a single autonomous station of 3 particle detecors. These data are compared with the simulation predictions investigating if a single antenna is capable for the estimation of the shower axis angular direction as well as the capability of this geometry to reconstruct the shower core, the energy and the mass of the primary particle.
During Run-2 the Large Hadron Collider (LHC) has provided, at the World's energy frontier, proton-proton collisions to the ATLAS experiment with high instantaneous luminosity (up to 2.1x10^34 cm^-2s^-1), placing stringent operational and physical requirements on the ATLAS trigger system in order to reduce the 40 MHz collision rate to a manageable event storage rate of 1 kHz, while not rejecting interesting collisions.
The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system with an output rate of up to 100 kHz and decision latency of less than 2.5 microseconds. Until the end of 2018, an important role was played by the Level 1 Topological Processor (L1Topo). This innovative system consists of two blades designed in AdvancedTCA form factor, mounting four individual state-of-the-art processors, and providing high input bandwidth and low latency data processing. Up to 128 topological trigger algorithms can be implemented to select interesting events by applying kinematic and angular requirements on electromagnetic clusters, hadronic jets, muons and total energy reconstructed in the ATLAS apparatus. This resulted in a significantly improved background event rejection rate and improved acceptance of physics signal events, despite the increasing luminosity. The L1Topo system has become more and more important for physics analyses making use of low energy objects, commonly present in the Heavy Flavour or Higgs physics events for example.
In this presentation, an overview of the L1Topo architecture, simulation, and performance results during Run-2 is discussed alongside with upgrade plans for the L1Topo system to be installed for the future data taking that will start in 2021.
Transverse missing momentum from non-interacting particles is one of the important characteristics for many analyses especially for Beyond Standard Model physics searches. To study these events at the Large Hadron Collider (LHC) with the ATLAS experiment an efficient trigger selection is needed. The ATLAS transverse missing momentum trigger uses calorimeter-based global energy sums together with specifically developed pile-up mitigation techniques. The high number of pile-up interactions was one of the major challenges faced during Run 2 and a continuous effort was needed to improve the pile-up rejection and to keep the trigger rate reasonable. This talk presents the techniques used to improve the Run 2 transverse missing momentum trigger performance, the full Run 2 performance and an outlook on further improvements for Run 3.
The CALorimetric Electron Telescope CALET is a space instrument designed to carry out precision measurements of high energy cosmic-rays on the JEM-EF external platform of the ISS where it has been collecting science data continuously since mid October 2015.
In addition to its primary goal of identifying nearby sources of high-energy electrons and possible signatures of dark matter in the electron spectrum, CALET is carrying out extensive measurements of the energy spectra, relative abundances and secondary-to-primary ratios of elements from proton to iron and above (up to Z=40) studying the details of galactic particle propagation and acceleration.
An overview of CALET based on the data taken during the first three years of observations is presented including a direct measurement of the electron+positron energy spectrum from 11 GeV to 4.8 TeV. The proton spectrum has been measured from 50 GeV to 10 TeV covering, for the first time with a single space-borne instrument, the whole energy interval previously investigated in separate sub-ranges by magnetic spectrometers and calorimetric instruments. Preliminary spectra of cosmic-ray nuclei are also presented, together with gamma-ray observations and searches of an e.m. counterpart of LIGO/Virgo GW events.
A variety of experiments have been developed over the past decades, aiming to detect Weakly Interactive Massive Particles (WIMPs) via their scattering in a detector medium. The sensitivity of these experiments has improved with a tremendous speed due to a constant development of the detectors and analysis methods. Detectors that are able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also give a proof of the galactic origin of dark matter making it possible to have a clear and unambiguous signal to background separation. The NEWSdm experiment, based on nuclear emulsions, is proposed to measure the direction of WIMP-induced nuclear recoils. We discuss the potentiality, both in terms of exclusion limits and potential discovery, of a directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching sub-micrometric resolution. We also report results of the test exposure conducted in Gran Sasso last year.
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. From February to July 2018, the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$, and Belle II has recorded a data sample of about 0.5 fb$^{-1}$. Main operation of SuperKEKB has started in March 2019.. Already this early data set with specifically designed triggers offers the possibility to search for a large variety of dark sector particles in the GeV mass range complementary to LHC and dedicated low energy experiments; these searches will benefit from more data in the process of being accumulated. This talk will review the state of the dark sector searches at Belle II with a focus on the discovery potential of the early data, and show the first results
The Sudbury Neutrino Observatory (SNO), built to study neutrinos produced in the Sun, discovered that neutrinos can change flavour and, thus, they are massive particles. SNO detected and recorded neutrino and cosmic ray interactions from 1999 to 2006 and several analyses have been completed in the past year using legacy data. We present the results of the most recent ones, namely: measurement of neutron production in atmospheric neutrino interactions, a search for Lorentz violation, and a search for potential neutrino decay. The former is important to better understand neutrino interactions and reduce backgrounds in supernova neutrino and nucleon decay searches, and the last two analyses yield new constraints on exotic physics searches. Finally, we will touch on the status of other on-going analyses.
The latets measurements coming from the B physics group will be shown in this talk.
Interesting results from data collected by CMS in different data taking periods will be discussed together with the possible perspective for the incoming years.
New results on jet fragmentation measurements at LHCb are presented. LHCb has probed the fragmentation of light and heavy flavour jets, with results showing significant discrepancies with theoretical predictions found using standard Monte Carlo event simulation. These are the first measurements of jet hadronisation and fragmentation at forward rapidities at the LHC. Results from LHCb of J/Psi production inside jets also provide a new handle on long-standing puzzles on accurately predicting J/Psi production in hadronic collisions.
Rare decays are powerful probes for Physics beyond the Standard Model
(SM), as new particles can have a large impact on physics observables.
Recent results on lepton universality tests and measurements of
branching fractions and angular distributions of rare b->sll decays have
shown tensions with the SM predictions. The LHCb experiment is ideally
suited for the study of the these flavour anomalies, due to its large
acceptance, precise vertexing and powerful particle identification
capabilities. This talk will review the latest results from LHCb on the flavour anomalies and their interpretation and will give a prospect of future measurements by LHCb.
In the NUMEN Experiment, a number of double Exchange reactions will be studied in order to get very precise measurements of their cross sections and final state levels. The interest for these reactions lies in the possibility for some nuclides, to have DCE with initial and final states identical to those of the Neutrino-less Double Beta Decay [1]. To reach a good precision in the energy measurements, high statistics is needed and severe constraints about the target thickness must be satisfied. The main sources of error are the straggling of projectiles and products and the dispersion effect inside the target. Both are related to the target thickness, which must be of the order of few hundreds nanometre. Moreover, the thickness uniformity plays a crucial role in the spread of the energy. The solution to these problems has been found by designing a target as a target isotope deposition on a substrate of special graphite (HOPG) [2], whose thermodynamic properties fit the cooling requirements [3]. The results of the chosen deposition technique (Electron Beam) for 116Sn, 130Te, 76Ge isotopes will be illustrated in terms of electron microscopy (FESEM) images. A more precise quantitative evaluation of the thickness distribution has been performed by Rutherford Back Scattering (RBS) and alpha-transmission measurements. The latter one allows to estimate also the thickness uniformity. In addition, a Montecarlo code has been implemented, aiming to estimate the precision of the measurements of the final states nuclear levels. The Montecarlo results will be reported in the talk for all the targets, together with the results of the tests of thickness and thickness uniformity, obtained with the above mentioned techniques.
[1] Cappuzzello F. et al., Eur. Phys. J. A, 54 (2018) 72, https://doi.org/10.1140/epja/i2018-12509-3
[2] F. Pinna et al., Design and test of an innovative static thin target for intense ion beams, Il Nuovo Cimento (2018), in press.
[3] V. Capirossi et al., Nucl. Instr, and Meth. in Phys. Res. A, (2018), in press. 2 https://doi.org/10.1016/j.nima.2018.08.081
The Large Hadron Collider at CERN along with all its experiments are in a shutdown period preparing for a large luminosity upgrade. This upgrade presents both challenges and opportunities to the experiments. For ALICE, this large increase in luminosity necessitates an upgrade in the electronics for many subsystems to cope with a much larger event rate. Additionally, the subsystems themselves are being upgraded or replaced to be able to run in these conditions and provide new capabilities. The inner tracking system of ALICE is being replaced to provide higher vertex and track pointing resolution and the time projection chamber is being upgraded to allow for continuous readout employing GEM detectors. These new capabilities along with the associated increase will open new avenues of study for ALICE concerning heavy-flavor, quarkonia, low mass dileptons, and jets. This talk will outline the current upgrade projects along with which new physics results can be expected from ALICE with the new high luminosity beams.
ALICE (A Large Ion Collider Experiment) is the CERN LHC experiment optimized for the study of the strongly interacting matter produced in heavy-ion collisions, in particular the characterization of the quark-gluon plasma. After the successful operation of the experiment during the first two runs of the LHC, the ALICE collaboration is currently working on a major upgrade of its detector, to be installed during the Long Shutdown (LS2) in 2019-2020. The main goal is to increase the readout capabilities to allow for the readout and recording of Pb–Pb minimum bias events at rates in excess of 50 kHz, the expected Pb–Pb interaction rate at the LHC after LS2. One key part of the upgrade is the construction of a new Inner Tracking System (ITS) that will significantly improve the impact parameter resolution, tracking efficiency and readout capacity enabling precise measurement of low momentum particles. The new ITS consists of seven approximately-cylindrical detector layers based on CMOS Monolithic Active Pixel Sensors (MAPS) with the sensor matrix and readout integrated in a single chip, named ALPIDE (ALice PIxel DEtector), with a pixel size of 29x27m2, covering an area of 10m2 and containing about 12.5 billion pixels. All layers are mounted on ultra-lightweight carbon support structures with an embedded cooling system. This allows a reduction of the material budget down to the 0.3 % X0 for the inner layers and 1% X0 for the outer layers.
This talk will give a brief overview of the motivation of the upgrade, give details on the overall layout and reports on both the construction and commissioning status and plans. Ideas on a further novel vertex detector based on curved wafer-scale ultra-thin silicon sensors will be illustrated.
Possible applications of the technologies, developed by the ALICE collaboration, will be also shown.
The Hwa-Kardar model of self-organised criticality is studied by the renormalization group analysis. The noise in the model under consideration is quenched, i.e., Gaussian one with correlation function $\left\langle ff\right\rangle\propto\delta^{(d)} ({\bf x-x'})$, where both ${\bf x}$ and ${\bf x}'$ are spatial coordinates and no dependence on time is presented. The effects of turbulent motion of the environment are taken into account. The advecting velocity field is described by Gaussian ensemble with finite correlation time.
Critical exponents are calculated in one-loop approximation. We show that depending on the relation between the exponent describing scaling behavior of the velocity field and the spatial dimension $d$, the system reveals different types of large-scale, long-time scaling behaviour, associated with the possible fixed points of the renormalization group equations.
It was recently shown that the BCS formalism leads to several solutions for the energy gap and the equilibrium quasiparticle distribution (D. V. Anghel, Physica A 464, 74, 2016; ibid. Physica A 2019). While this became quite obvious when the attraction band (which is the single-particle energy interval in which the pairing interaction is manifested) is asymmetric with respect to the chemical potential of the system (that is, the center of the attraction band $\mu$ is different from the chemical potential $\mu_R$), I will show here that there are two solutions, with different energy gaps and quasiparticle populations even when $\mu = \mu_R$. One of the solution leads to the well-known BCS results, with an energy gap denoted here by $\Delta_1(\mu_R-\mu = 0, T)$ (where $T$ is the temperature), whereas the second one leads to an energy gap $\Delta_2(\mu_R-\mu = 0, T) \le \Delta_1(\mu_R-\mu = 0, T)$, for any $T$ below the critical temperature -- the critical temperature is the same for both solutions. In the second solution, the quasiparticle population is different from zero even at $T=0$ and it was shown before (D. V. Anghel, Phyica A, 2019) that $\Delta_2(\mu_R-\mu = 0, T=0) = \Delta_1(\mu_R-\mu = 0, T=0)/3$.
The light-cone definition of Parton Distribution Functions (PDFs) does not allow for a direct ab initio determination employing methods of Lattice QCD simulations that naturally take place in Euclidean spacetime. In this presentation we focus on pseudo-PDFs where the starting point is the equal time hadronic matrix element with the quark and anti-quark fields separated by a finite distance. We focus on Ioffe-time distributions, which are functions of the Ioffe-time ν, and can be understood as the Fourier transforms of parton distribution functions with respect to the momentum fraction variable x. We present lattice results for the case of the nucleon and we also perform a comparison with the pertinent phenomenological determinations.
The chiral vortical effect (CVE), separation of right- and left-handed fermions in chiral media, is belived to be intrinsically related to the anomalies of the axial current and the topological properties of the system. It was suggested that CVE can be generalized to systems of higher-spin particles and, particularly, to systems of photons. However, there is no local gauge invariant definition of photonic helicity current. This problem can be overcome with an appropriate choice of the polarization measure. Recently,it was shown that there is a vortical effect in photonic zilch current (ZVE), which can play the role of a local gauge invariant helicity separation measure. In this work we study the zilch current in terms of chiral kinetic theory and show that ZVE can be related to the non-trivial topological properties of the system in momentum space manifested through the Berry phase.
We consider a few theoretical issues related to the physics of heavy-ion collisions.
The emphasis is on predictions for microscopic variables, especially spin variables, and their dependence on the overall rotation and/or acceleration of the quark-gluon medium. In case of the rotation, as a manifestation of the low viscocity the central role is played by vortices. In case of the acceleration, we concentrate on the instability of the medium due to the Unruh effect.
Relativistic heavy-ion collision events containing rare final states involving high transverse momentum objects provide in situ probe which allow haracterization of the hot, dense QCD matter formed in these collisions. When compared with comparable yields in proton-lead and proton-proton collisions, hadronic jets and quarkonia (both for charm and bottom quarks) are observed to have significantly modified yields and fragmentation properties in lead-lead collisions. Details of these modifications carry information about the interaction of partons with the medium as well as the properties of the medium. By comparison, yields of photons and massive electroweak bosons in lead-lead and proton-lead collisions are found to be essentially unmodified compared to expectations, including isospin effects. With increasing integrated luminosities, these measurements can be used to measure nuclear parton distribution functions and other geometric aspects of the initial state. This talk will present the most recent results on quarkonia, jet, heavy flavor and electroweak boson production, measured in Pb+Pb and p+Pb collisions. The talk also covers the recent results on the observation of the light-by-light scattering process in lead-lead collisions at $\sqrt{s_{NN}} = 5.02$ TeV. The analysis is conducted using 1.73 nb$^{-1}$ of data collected in November 2018 by the ATLAS experiment at the LHC. Light-by-light scattering event candidates are selected in events with two photons produced exclusively, with small diphoton transverse momentum and small acoplanarity. After applying all selection criteria, 59 candidate events are observed for a background expectation of 12 $\pm$ 3 events. An excess of events over the expected background is found with an observed significance of 8.2 standard deviations. The fiducial cross section is also measured and compared to the theoretical predictions.
Resolving singularities in General Relativity
Stochastic gravitational waves can be produced during the preheating when out-of-equilibrium particles are produced with an anisotropic stress-tensor. We discuss the case where these particles carry spin 3/2. We compute the spectrum of the gravitational waves generated by the transverse and longitudinal components. We find a different scaling of the spectrum near the peak and the longitudinal components lead to an enhancement when compared to spin-1/2 fermions with Yukawa couplings. We note, as expected, that the corresponding typical frequency is too high for the current observation and calls for ultra-high frequency gravitational wave detectors in the future.
Inertial Confinement Fusion is a promising option to provide massive, clean, and affordable energy for humanity in the future. The present status of research and development is hindered by hydrodynamic instabilities occurring at the intense compression of the target fuel by energetic laser beams. A recent proposal Csernai et al. (2018) combines advances in two fields: detonations in relativistic fluid dynamics and radiative energy deposition by plasmonic nano-shells. The initial compression of the target pellet can be eliminated or decreased, not to reach instabilities. A final and more energetic laser pulse can achieve rapid volume ignition, which should be as short as the penetration time of the light across the target. In the present study, we discuss a flat fuel target irradiated from both sides simultaneously. Here we propose an ignition energy with smaller compression, largely increased entropy and temperature increase, and instead of external indirect heating and huge energy loss, a maximized internal heating in the target with the help of recent advances in nano-technology. The reflectivity of the target can be made negligible, and the absorptivity can be increased by one or two orders of magnitude by plasmonic nano-shells embedded in the target fuel. Thus, higher ignition temperature and radiation dominated dynamics can be achieved. Here most of the interior will reach the ignition temperature simultaneously based on the results of relativistic fluid dynamics. This makes the development of any kind of instability impossible, which up to now prevented the complete ignition of the target.
Recent Measurements Hadronic Resonances with ALICE at the LHC
Bong-Hwi Lim$^{*}$ on behalf of ALICE collaboration
*Pusan National University
Hadronic resonances are useful probe to study the properties of the late hadronic phase in ultra-relativistic heavy-ion collisions. The resonances have lifetimes comparable to the time scale of the fireball, so they are sensitive to the competing effects of re-scattering and re-generation in the hadron gas, which can affect the final yields and momentum distributions of resonances. Hadronic resonances with different masses, quantum numbers and quark content can be compared to ground-state particles to provide information about different aspects of ion-ion collisions. In addition, the results from high-multiplicity proton-proton (pp) collisions will be presented to investigate the possible onset of collective phenomena in small systems.
In this contribution, the latest ALICE results on $\rm{f}_{0}(980)$, $\rm{f}_{2}(1270)$, $\rm{\rho}(770)$, charged and neutral $\rm{K}^{*}(892)$, $\Phi(1020)$, $\rm{\Sigma}(1385)^{\pm}$, $\rm{\Lambda}(1520)$, $\rm{\Xi}(1530)^{0}$ measured in pp, p--Pb, Pb--Pb and Xe--Xe collisions at different collision energies will be presented and compared to results from other experiments and theoretical models.
The ALICE experiment has measured a variety of (anti-)(hyper-)nuclei produced in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV and at 2.76 TeV. In addition, a large sample of high-quality data was recorded in pp collisions at $\sqrt{s}$ =5.02, 7 and 13 TeV and in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. These data are used to study the production of (anti-)deuteron, (anti-)$^{3}\rm{He}$, (anti-)$^{4}\rm{He}$ and (anti-)hypertriton.
The identification of these (anti-)(hyper-)nuclei is based on the energy loss measurements in the Time Projection Chamber and the velocity measurements in the Time-Of-Flight detector. In addition, the Inner Tracking System is used to distinguish secondary vertices originating from weak decays away from the primary vertex.
An interesting collection of results on deuteron production as a function of multiplicity in pp, p-Pb and Pb-Pb collisions will be presented, as well as the measurement of $^{3}\rm{He}$ in p-Pb and Pb-Pb collisions. Special emphasis will be put on new results on the production and lifetime of the hypertriton.
The large variety of measurements at different energies and system sizes allows us to constrain the models of the production mechanism of light flavour baryon clusters, in particular those based on coalescence and the statistical hadronisation approaches.
Heavy flavor production is a sensitive probe of the initial gluon density
in the nucleon and is affected by the entire evolution of the collision.
Besides, it is a process which can be calculated by perturbative QCD
because of their large mass.
The PHENIX experiment at RHIC studied the heavy flavor production
for a broad momentum and rapidity ranges using its semileptonic and
$J/\psi$ decays in $p+p$, $p+A$ and $Au+Au$ collisions
at $\sqrt{s_{NN}}$=200GeV.
In this talk, the recent experimental results will be presented
and compared with theoretical models which describe
heavy quark production, gluon distribution modifications
in nucleus and its energy loss in the medium created in Au+Au collisions.
The experiments at RHIC and LHC have produced convincing evidence that strongly interacting partonic matter, Quark Gluon Plasma (QGP), is created in central ultrarelativistic collisions of heavy ions. Charm quarks are ideal probe of the QGP since they are dominantly produced in hard gluon-gluon interactions in early stages of nuclear collisions at RHIC energies. Therefore, they are sensitive to the whole evolution of the hot and dense matter. Thanks to the excellent vertex resolution provided by the Heavy Flavor Tracker detector, STAR is able to measure charm quark production in multiple channels via reconstruction of hadronic decays of D0, D+/-,Ds and Lambda_c hadrons. In this talk we will present recent STAR measurements of nuclear modification factors of D0 and D+/- mesons, D0 directed, elliptic and triangular flow and Ds/D0 and Lambda_c/D0 yield ratios. These measurements will be discussed in context of charm quark energy loss, charm quark transport in the QGP and final hadronization.
We report the results of Quantum Monte Carlo (QMC) simulations of graphene at large-scale lattices. In our study we accessed small enough temperatures and momenta to confirm the logarithmic divergence of the Fermi velocity at low energies in the non-perturbative regime. It appears that our QMC results lie in between predictions made by one-loop lattice perturbation theory (which substantially overestimates the effect) and Random Phase Approximation (RPA). We also probed the influence of short-range interactions on the long-range behavior of the Fermi velocity, by performing QMC calculations with the same long-range Coulomb tail but different cutoffs for the potentials at short distances.
Longitudinal and transverse gluon propagators are investigated in QC_2D at high baryon density and zero temperature as functions of the baryon chemical potential and momentum. A particular attention is concentrated on the region of the confinement-deconfinement transition recenly found in this model. The behavior of electric and magnetic screening masses is discussed.
Graphene, a system of carbon atoms arranged on a two dimensional hexagonal lattice, has been the subject of intense theoretical and experimental research in the past decade, due to its unique electronic properties. The special symmetries of its electronic band structure lead to an effective description in terms of a massless Dirac field, and strong inter-electron interactions, which can be tuned through various experimental techniques, drive quantum phase transitions to different gapped electronic ordered phases. The phase diagram of interacting fermions on a hexagonal lattice can be studied from first principles using Hybrid-Monte-Carlo simulations. Here, the present status of these efforts is reported.
We numerically study finite volume effects on transport properties of chiral fermions. To this end, we compute anomalous transport coefficients in linear response approximation, both in continuum and on the lattice using Wilson-Dirac and Overlap fermions. We analyze stability of plasma of chiral (lattice) fermions coupled to dynamical gauge fields and find that finite volume effects significantly impact lattice simulations of dynamical decay of chiral charge due to Chiral Magnetic Instability. We confront our results to real-time lattice simulation in the framework of classical-statistical field theory.
Since new coloured states have been strongly constrained by LHC searches, extended electroweak sectors have become of paramount interest. However, the quantum corrections to these sectors can be very large; in the classic example of the MSSM, the Higgs mass has very large corrections at two loop order. On the other hand, in the MSSM, or even in the Two Higgs Doublet Model, the electroweak corrections to the Higgs mass have never been completely calculated. I will present the calculation of scalar self-energies and tadpoles for general renormalisable theories at two loop order without approximations.
In this work we consider a warped five-dimensional model with an ultraviolet (UV) brane and, on top of the Standard Model zero modes, continua of KK modes with different mass gaps for all particles: gauge bosons, fermions, graviton, radion and Higgs boson. The model can be considered as a modelization in five dimensions of gapped unparticles. It has a singularity, at a finite (infinite) value of the proper (conformal) coordinate, which is admissible as it supports finite temperature in the form of a black hole horizon. An infrared (IR) brane, with particular jumping conditions, is introduced to trigger correct electroweak breaking. The gravitational metric is AdS$_5$ near the UV brane, to solve the hierarchy problem with a fundamental Planck scale, and linear, in conformal coordinates, near the IR, as in the linear dilaton and five-dimensional clockwork models. The branes, and singularity, distances are fixed, a la Goldberger-Wise, by a bulk scalar field with brane potentials explicitly breaking the conformal symmetry. We have computed the spectral functions and arbitrary Green's functions and shown how they can modify some Standard Model processes. This work is based on [1]. Related works are [2,3,4].
*References:
[1] E. Megias, M. Quiros, arXiv:1905.XXXXX (to appear).
[2] L. Randall, R. Sundrum, "A Larga mass hierarchy from a small extra dimension", PRL 83 (1999) 3370-3373.
[3] C. Csaki et al., "Continuum Naturalness", JHEP 1903 (2019) 142.
[4] G. Giudice et al, "Clockwork / Linear Dilaton: Structure and Phenomenology", JHEP 1806 (2018) 009.
TBA
Primordial Intermediate Black Holes as Dark Matter
It is known that de Sitter solutions in supergravity require supersymmetry breaking. I will present a new construction that allows the inclusion of the goldstino into supergravity, based on applying the Stueckelberg trick to a novel superfield formulation of unimodular supergravity. I will show the existence of de Sitter solutions and also the connection to the Volkov-Akulov model in the flat limit of our theory.
Review of the recent results of hadronic cross section measurements with the CMD-3 detector at the e+e− collider VEPP-2000 is presented. The main focus is on the study of the processes with charged pions and kaons in multihadron events, which have a strong impact on the meson spectroscopy with light quarks and form factors. The exclusive K+K −(nπ) final states are the special interest since their production involves the rich intermediate dynamics that allows to test the isotopic relations and to measure their parameters. Experimental data relevant to the topic are presented in the broad energy range covered by the collider and they are compared with earlier measurements of different collaborations. The analysis is based on the integrated luminosity of about 100 pb−1 collected in runs 2011, 2012 and 2017.
The large data sample accumulated by the Belle experiment at KEKB
asymmetric energy e^+ e^- collider provides opportunities to study
bottomonia and bottomonium-like exotic particles. In this presentation,
we report recent results on these topics from Belle, including a new
measurement of the e^+e^-\to \Upsilon(nS)\pi^+\pi^- (n=1,2,3) cross
sections at energies from 10.52 to 11.02 GeV, and observation of
ϒ(2S)→γ ηb(1S), ϒ(4S) → η'ϒ(1S) and e+e-→π+π-π0χb1,2(1P).
A program of measuring the light hadrons production in exclusive e+e -> hadrons
processes is continuing with the BABAR data, with the aim to improve the
calculation of the hadronic contribution to the muon g-2. We present the most
recent results obtained by using the full data set of about 470 fb-1 collected
by the BABAR experiment at the PEP-II e+e- collider at a center-of-mass
energy of about 10.6 GeV. In particular, we report the results on the channels
e+e -> pi+pi-pi0pi0, pi+pi-pi0pi0pi0(eta), e+e-> pi_pi-eta. Additionally, we
present the study of the two-photon process e+e- -> e+e-eta(958) in the
double-tag mode. The results for the form factor are compared with the
predictions based on pQCD and VMD.
We present recent NOMAD measurements on neutrino-induced coherent
production of $\pi^0$, $\rho^+$ and $\rho^0$ mesons. The NOMAD detector
is based upon a low density design (0.1 g/cm^3) offering excellent momentum,
energy and angular resolutions, which are well suited for the measurement
of the coherent production processes.
The new NOMAD measurements are compared with different models for the
coherent scattering off nuclei, in which all nucleons participate in the interaction and the
nucleus recoils intact. These measurements can also provide a test of our
understanding of the weak current at small momentum transfer, namely the PCAC and CVC hypotheses, which are used to model the processes. As a utilitarian application of the measurements, we will discuss the use of coherent $\pi$ and $\rho$ to provide constraints on neutrino fluxes and energy scales.
Neutrinoless double beta (0νββ) decay is a process in which a nucleus (A,Z) decays to (A,Z+2) with the emission of two electrons (but no neutrinos). Experimental searches for such a decay are the most sensitive test of lepton-number conservation and its discovery would unambiguously prove the Majorana nature of neutrinos, with profound implications for cosmology in addition to particle and nuclear physics. This process is also a sensitive probe of the absolute neutrino mass scale.
EXO (Enriched Xenon Observatory) is an experimental program searching for 0νββ decay of 136Xe. After a successful 200-kg experiment (EXO-200), a next generation experiment, nEXO, is proposed and in advanced design phase. nEXO is a 5-tonne liquid xenon TPC with a sensitivity to the 0νββ decay half-life of 136Xe of ~10^28 years. It builds on the EXO-200 experience while introducing novel technical solutions, such as the use of VUV-sensitive silicon photomultipliers (SiPMs) placed behind an optically open electric filed shaping electrode structure, a novel planar tiled charge collection system, in-xenon low-radioactivity cryogenic read out electronics, and minimal use of plastic materials to minimize the outgassing of electronegative impurities into the LXe volume.
This talk introduces the physics case for the investigation of neutrinoless double beta decay and overviews the nEXO design and expected sensitivity.
The GERDA (GERmanium Detector Array) experiment, located at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, is one of the leading experiments searching for neutrinoless double beta decay (0νββ). Bare semiconductor detectors made of germanium enriched in Ge-76 isotope are operated in a cryostat filled with liquid argon. In Phase II of the experiment 35.6 kg of enriched germanium detectors are deployed. Application of active background rejection methods, such as a liquid argon scintillation light read-out and pulse shape discrimination of detector signals, allowed to reduce the background index to less than 10^-3 cts/(keV·kg·yr). The half-life sensitivity for 0νββ decay achieved by GERDA Phase II overpassed 10^26 years first time ever. Recently the hardware upgrade of the experiment has been performed. At the conference the status of GERDA Phase II after the upgrade will be presented.
Many theories beyond the Standard Model predict new phenomena which decay to quarks. Light-quarks 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. On the other hand, b- and top-quarks offer great potential to reduce the Standard Model background, although with significant challenges in reconstructing and identifying the decay products and modelling the remaining background. Recent searches in various hadronic final states performed with the ATLAS experiment at the LHC on the 13 TeV data will be presented, along with some prospects for HL-LHC.
We consider the generalization of the Minimal Supersymmetric Standard Model with spontaneous supersymmetry breaking in some hidden sector. After all heavy fields from hidden sector are integrated out, only fields from SM, MSSM and goldstino multiplet remain in the model. We discuss the possibility of di-Higgs production amplification via process gg $\rightarrow$ s $\rightarrow$ hh with scalar particle sgoldstino, which is the superpartner of goldstino fermion. In this process sgoldstino is produced by gluon fusion and then decays to a pair of light neutral (SM) Higgs bosons. We observe two possible regimes of sgoldstino decays depending on parameter choice: domination of gluon decay mode and production of pairs of light neutral Higgs bosons, W-bosons and Z-bosons in relation 1:2:1. We give numerical estimates for borders of regions corresponding to these regimes in parameter space. We also obtain an upper limit for $M_3/F$ and a lower limit for $\sqrt{F}$ from experimental searches for heavy scalar resonances and determination of gluino mass made by the ATLAS and the CMS collaborations.
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. With this data set, Belle II will be able to measure the Cabibbo-Kobayashi-Maskawa (CKM) matrix, the matrix elements and their phases, with unprecedented precision and explore flavor physics with $B$ and charmed mesons, and $\tau$ leptons. Belle II has also a unique capability to search for low mass dark matter and low mass mediators. From February to July 2018, the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$, and Belle II has recorded a data sample of about 0.5 fb$^{-1}$. Regular operations, with full detector, have started in March 2019. In this presentation, we will review the status of the Belle II detector, the results from the early data, and the prospects for the study of rare decays , in the quest of uncovering New Physics.
strong textIn the Standard Model of particle physics, CP violation arises due to a single complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix. Testing the validity of the CKM mechanism as the only source of CP violation is one of the major experimental challenges in particle physics today. Precise measurement of the CKM parameters therefore constrains the Standard Model, and may reveal effects beyond the Standard Model. Measurement of the time¿dependent decay rates of Bs0 ->J/psi phi provides a theoretically clean method for extracting CP¿violating weak mixing phase phi_s. The Standard Model predicts phi_s to be very small and it is very well constrained, while in many new physics models large phi_s values are expected. Bs0¿>J/psi phi decay channel is sensitive to the new physics contributions, and already small deviations in a measurement of phi_s would be hints for the existence of the new particles. The most recent results from ATLAS are presented in CP-violating mixing phase phi_s and several other parameters describing the Bs0 meson system.
The data acquired in 2015-2017 years in pp-collisions at 13 TeV are analysed, it gives improvement by a factor of 2 in precision of phi_s measurement in comparison with previous analysis on Run 1 data. This measurement compared with recent LHCb result and other experiments.
Study of the dynamics of hadron formation explores the connection between properties of QCD field and a number of observables ranging from inclusive
distributions through correlations to the mass spectra of hadrons.
It is shown how dedicated measurements constrain the hadronization model, typically by combination of several observables. The choice of observables and their sensitivity to the hadronization is discussed.
Understanding the energy loss of partons traversing the strongly interacting matter created in heavy ion collisions is one of key goals of the heavy ion physics program. After a brief introduction to the field and explaining connections of heavy ion physics and high-energy QCD physics, we present results of phenomenological analyses of various recent jet quenching data. The core of the model used in these analyses is based on the shift formalism which allows for an extraction of the magnitude of parton energy loss from the data with minimal assumptions on the underlying physics mechanisms. The model accurately reproduces jet $R_{AA}$ and its $p_{T}$ and rapidity dependence, shape of the modification of fragmentation functions observed in the data and, consequently, the $R_{AA}$ of charged particles. The analysis of recent data on splitting functions and fragmentation functions allows for further constrains on the role of coherence effects in the parton energy loss. Further, the analysis of charmonia suppression using this model points to a remarkable similarity between the quenching of light-quark-initiated jets and the prompt charmonia suppression. This may bring an insight into both the suppression mechanism and general aspects of charmonia formation which is still not well understood.
We consider a model of an artificial neural network that uses quantum-mechanical particles in a two-humped potential as a neuron. To simulate such a quantum-mechanical system the Monte-Carlo integration method is used. A form of the self-potential of a particle and two potentials (exciting and inhibiting) interaction are proposed. The possibility of implementing the simplest logical elements, (such as AND, OR and NOT) based on introduced quantum particles is shown. Further we show implementation of a simplest convolutional network. Finally we construct a network that recognizes handwritten symbols, which shows that in the case of simple architectures, it is possible to transfer weights from a classical network to a quantum one.
Machine learning (ML) has been recently used as a very effective tool for the study and prediction of data in various fields of physics, from statistical physics to theoretical high energy physics. We investigate the use of deep learning autoencoders for the unsupervised recognition of phase transitions in physical systems formulated on a lattice. We use spin configurations produced for the 2-dimensional ferromagnetic Ising model in zero external magnetic field. We study numerically the relation between one latent dimension to the critical temperature $T_c$. The autoencoder reveals the two phases, one for which the spins are ordered and the other for which spins are disordered, reflecting the restoration of the $Z_2$ symmetry as the temperature increases. For the our largest volume, the transition between the two phases occurs very close to the analytically extracted critical temperature. We identify as a quasi-order parameter the absolute average latent dimension enabling us to predict the critical temperature.
JLab measurement of the ratio of the nucleon structure functions, $F_2^n$ / $F_2^p$, from electron DIS off 3H and 3He at large Bjorken x
Measurement of the EMC effect of the $^3$H nucleus from the JLab MARATHON experiment
Measurement of the EMC effect of the $^3$He nucleus from the JLab MARATHON experiment
The latest results on production of Higgs boson pairs at 13 TeV by the ATLAS experiment are reported, including a combination of six different decay modes. Results include bbtautau, bbbb, bbgamgam, bbWW, WWWW and WWgamgam final states, and they are interpreted both in terms of sensitivity to the SM and as limits on kappa_lambda, a scaling of the triple-Higgs interaction strength. A new search dedicated to the Vector-Boson-Fusion production was performed in the bbbb final state. Future prospects of testing the Higgs self-couplings at the High Luminosity LHC (HL-LHC) will also be presented.
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. $H \to\mu\mu$. In addition, theories beyond the Standard Model may predict lepton-flavor violating decays of the Higgs boson. Results for these searches based on pp collision data collected at 13 TeV will be presented.
The AMADEUS and SIDDHARTA-2 collaborations aim to provide experimental information on the low-energy strong interaction between antikaons and nucleons. The investigation of the antikaons dynamics in nuclear medium is fundamental for understanding the non-perturbative QCD in the strangeness sector, with implications going from the domain of nuclear physics to astrophysics. The DA$\Phi$NE collider provides a unique source of monochromatic low-momentum kaons (p$_K$ ~ 127 MeV/c) from the $\phi$-meson decay nearly at-rest, ideal to explore the interactions of the kaons at low-energy or to stop them in the targets. SIDDHARTA-2, which is the upgraded experiment of SIDDHARTA, studies the physics of kaonic atoms. The goal is to measure the X-rays emitted in the atomic transitions of the kaonic deuterium, the energy shift and the width of the 1s level will allow to extract for the first time the isospin dependence of the KbarN scattering amplitude at the threshold. AMADEUS explores the absorptions of the K$^-$ in light nuclei (H, $^4$He, $^9$Be and $^{12}$C) in order to extract information about the possible existence of kaonic bound states with nucleons and the properties of hyperon resonances in the nuclear environment. As a first step, the hadronic interactions of the negatively charged kaons with the materials of the KLOE detector, used as an active target, are investigated through hyperon-nucleon/nuclei (YN) and hyperon-pion (Y$\pi$) correlation studies.
SNO+ is a multi-purpose experiment whose main purpose is to study the nature of the neutrino mass through observation of neutrino-less double beta decay (0$\nu\beta\beta$). Detection of this rare process would indicate that neutrinos are elementary Majorana particles, proving that lepton number is not conserved and providing an estimate of their unknown absolute mass. The SNO+ detector will operate in three distinct phases with different target materials: water, pure scintillator (LABPPO) and tellurium-loaded scintillator. We will report results on the measurement of the radioactive backgrounds, as well as, the results of the solar neutrino and invisible nucleon decay analyses, performed during the water phase, now concluded. Furthermore, the status, potential and prospect of SNO+ for precise solar neutrino measurements and 0$\nu\beta\beta$ search will be presented.
The Sun offers us the opportunity to make detailed observations of the exterior and interior of a typical star in its mid-life phase. A unique way to study the innermost regions of our star is offered by solar neutrinos, emitted by the thermonuclear fusion reactions in the Sun. The Borexino experiment, located in Laboratori Nazionali del GranSasso in Italy and widely known for its rich Solar Neutrino physics program, is now in his high-purity Phase II, thanks to intense purification campaigns of scintillator that were very successful in further reducing the already low backgrounds, leading to unprecedented radiopurity levels reached in its active volume (<10^19 g/g for 238U/232Th chains).
In this talk I will review the latest result released, the first simultaneous measurement of the neutrino interaction rates from the proton-proton chain, and I will present the strategies for measuring the neutrino flux from the CNO cycle, the last one not yet measured. The detection of these neutrinos has important implications in astrophysics, as it would be the first direct evidence of the nuclear process that is believed to fuel massive stars.
Despite the unprecedented low levels of background reached in the detector, the CNO solar neutrinos detection remains a very challenging task because of the almost degenerate spectral shapes of the signal due to CNO neutrinos and the 210Bi background, so that spectral fits are not able to disentangle the two contributions. A realistic measurement of CNO neutrinos can be performed only using a multivariate spectral fit supported by a sensitive pulse shape discrimination. The 210Bi background can be reduced by further purifications of the scintillator, but anyway it must be also constrained independently by measuring the rate of decay of the daughter nucleus, the 210Po. The difficulty of this analysis lies both in the low signal to noise ratio and in the contamination of the 210Po in the vessel, which diffuses towards the center of the detector. Such transport was strongly suppressed after the detector was equipped with thermal insulation yet this effect remains non-negligible.
TBA
Prospects, Design and Status of JUNO
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton multi-purpose liquid scintillator detector currently being built in a dedicated underground laboratory in Jiangmen (PR China). Data taking is expected to start in 2021. JUNO’ s main physics goal is the determination of the neutrino mass ordering using electron anti-neutrinos from two nuclear power plants at a baseline of about 53 km. JUNO aims for an unprecedented energy resolution of 3% at 1 MeV for the central detector, to be able to determine the mass ordering with 3 - 4 \sigma significance within six years of operation.
Besides this fundamental aim, JUNO will have a very rich physics program. It includes the measurement (at a sub-percent level) of the solar neutrino oscillation parameters, the detection of low-energy neutrinos coming from galactic core-collapse supernovae, the first measurement of the diffuse supernova neutrino background, the detection of neutrinos coming from the Sun, the Earth and the Earth's atmosphere. Moreover JUNO will be sensitive to searches for nucleon decays and neutrinos resulting from dark matter annihilation in the Sun.
In this talk JUNO’s design, physics prospects as well as the status of its construction will be presented, together with a short excursion into its rich R&D program.
The exploration of the QCD phase diagram has been one of the main drivers of contemporary nuclear physics. Heavy-ion collisions provide a powerful tool to explore phase structures of strongly interacting hot and dense nuclear matter called Quark-Gluon Plasma (QGP).
The Relativistic Heavy Ion Collider (RHIC) is uniquely suited to map the QCD phase diagram by varying the energy of collisions, as well as nuclei species. In this talk, we will present the most recent results from the STAR experiment at RHIC and discuss future plans.
Unruh Instability
Shear viscosity of hot and dense nuclear matter, produced in the central zone of central gold-gold collisions at energies of NICA, is calculated within the UrQMD model. Besides the microscopic simulations of heavy ion collisions, the procedure assumes the application of statistical model to determine the temperature and chemical potentials in the system, and study of the relaxation process within the UrQMD box with periodic boundary conditions. The latter is used for calculation of the correlator which enters the Green-Kubo formula for shear viscosity. The fluctuations at early and late stages of the system evolution are studied. Results are compared to predictions of other models.
During last few years two groups based on many irregularities and possible signals independently suggested that the 1-st order phase transition of chiral symmetry restoration in hadronic phase may occur in the central nuclear collisions at the center-of-mass energies 3.8–4.9 GeV [1-8], while a weaker deconfinement phase transition of 2-nd order may be reached at the center-of-mass collision energies 9-10 GeV [1-8]. Later on the third group studying the fluctuations of light nuclei concluded that the center-of-mass collision energy 8.8 GeV may be the nearest vicinity of the critical endpoint of QCD matter phase diagram [9]. Very recently the energy dependence of the shear viscosity η to entropy density s ratio η/s was found at the chemical freeze-out curve [10]. This ratio shows two local minima located at the the center-of-mass collision energies 3.8–4.9 GeV and 9-10 GeV, which provide an independent evidence that two QCD phase transitions occur at these collision energies.
In this lecture we discuss the most remarkable irregularities at chemical freeze-out suggested in Refs. [1-8]. The most prominent of them are the sharp peaks of the trace anomaly and baryonic charge density existing at chemical freeze-out at the center-of-mass energies 4.9 GeV and 9.2 GeV [1, 2]. They are accompanied by two sets of highly correlated quasi-plateaus in the collision energy dependence of the entropy per baryon, total pion number per baryon, and thermal pion number per baryon which are found at the center-of-mass energies 3.8–4.9 GeV and 7.6–9.2 GeV [1-3]. The low-energy set of quasi-plateaus was predicted a long time ago. On the basis of the generalized shock-adiabat model it is shown that the low-energy correlated quasi-plateaus provide the evidence for the anomalous thermodynamic properties inside the mixed phase reached at the center-of-mass energies 4.3–4.9 GeV. Furthermore, using the thermostatic properties of the mixed phase of a 1-st order phase transition and the ones of the Hagedorn mass spectrum we explain, respectively, the reason of observed chemical equilibration of strangeness at the collision energy 4.9 GeV and above 8.7 GeV [4]. Also we argue that both sets of irregularities possibly evidence for two QCD phase transitions mentioned above. In combination with a recent analysis of the light nuclei number fluctuations [9] our results suggest that the center-of-mass collision energy range 8.8-9.2 GeV may be in the nearest vicinity of the QCD tricritical endpoint [4].
K. A. Bugaev, A. I. Ivanytskyi, D. R. Oliinychenko, V. V. Sagun, I. N. Mishustin, D. H. Rischke, L. M. Satarov and G. M. Zinovjev, Phys. Part. Nucl. Lett. 12, (2015) 238.
K. A. Bugaev, A. I. Ivanytskyi, D. R. Oliinychenko, V. V. Sagun, I. N. Mishustin, D. H. Rischke, L. M. Satarov and G. M. Zinovjev, Eur. Phys. J. A 52, (2016) 175.
K. A. Bugaev, V.V. Sagun, A. I. Ivanytskyi, D. R. Oliinychenko, E.-M. Ilgenfritz, E. G. Nikonov, A.V. Taranenko and G. M. Zinovjev, Eur. Phys. J. A 52, (2016) 227.
TBA
Public Talk by Prof. Viacheslav Mukhanov "How predictive cosmological theories are?" in OAC amphitheater 18:45-19:45
TBA
For an isotropic cosmological model with a spatial curvature supported by a self-interacting scalar field minimally coupled to gravity, we construct and analyze a special integrable potential which approximates the potential of the Starobinsky R+R^2 inflationary model in the Einstein frame, and derive the general analytic solution of the corresponding Einstein–Friedmann equations. We demonstrate that there exists a three–dimensional domain in the space of three model parameters describing the general solution for which the model possesses both inflationary stages and bounces and has no singularities.
The NICA Complex is under construction at the Joint Institute for Nuclear
Research in Dubna. The Complex comprises a chain of accelerators – the
Nuclotron, the Booster and the Collider, and three detectors, two of which,
the Baryonic Matter at Nuclotron (BM@N) and the Multi Purpose Detector (MPD),
are dedicated to study heavy ion collisions.
The Nuclotron provides variety of extracted ion beams up to kinetic energy
of 4.4 GeV per nucleon to the running experiment BM@N. The MPD detector is
under construction and will be located at the first interaction point of the Collider.
It is dedicated to study hot and baryon rich QCD matter in heavy-ion collisions in the energy
range (√sNN)=4−11GeV.
The status of NICA Complex construction and prospects for physics program
are presented.
The Compressed Baryonic Matter (CBM) experiment is of the major scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the properties of nuclear matter at neutron star core densities using high-energy nucleus-nucleus collisions. This includes the study of the high-density equation-of-state (EOS) of nuclear matter, and the search for new phases of QCD matter at high densities. Up to now, the EOS of symmetric nuclear matter and the symmetry energy have been studied in the laboratory up to twice saturation density. However, the core density of massive neutron stars is expected to exceed five times the density of an atomic nucleus. These densities can be produced in collisions between heavy nuclei at FAIR energies. Promising experimental observables sensitive to the EOS and to the symmetry energy will be discussed, together with the expected performance of the CBM experiment.
Many theories beyond the Standard Model (BSM) predict new phenomena accessible by the LHC. Searches for new physics models are performed using the ATLAS experiment at the LHC focusing on exotic signatures that can be realized in several BSM theories, excluding supersymmetry. The results of recent searches on 13 TeV data, with the exception of Dark Matter signatures, and their interplay and interpretation will be presented. Prospects for HL-LHC will also be discussed.
CMS, as one of the two LHC muti-purpose experiments, has recorded a large amount of pp-collision data at sqrt(s)=13 TeV in Run-2. This unprecendented dataset is used to search for new physics in a large variety of final states.Heavy vector bosons are predicted by many models and serve as a candle for high-pT physics.Leptoquarks are a potential explaination for the observations in the flavour sector. Unusual signatures, such as displaced or delayed particles, allow to increase the access to models.This presentation reviews the latest results from new physics searches with CMS.
The top quark is the heaviest known fundamental particle. As it is the only quark that decays before it hadronizes, it provides the unique opportunity to probe the properties of bare quarks at the Large Hadron Collider. This talk will present highlights of a few recent precision measurements of the top quark using 13 TeV collision data with the ATLAS experiment: top-quark pair and single top production cross sections, including differential distributions and production in association with bosons, will be presented alongside top quark properties measurements. Measurements of the top-quark mass and searches for rare top decays are also presented.
Precision electroweak measurements are among the main goals of the Large Hadron Collider physics program. In this talk the most recent results obtained by the CMS experiment with Drell-Yan, W and multi-bosons events will be reviewed. These include the measurement of the electroweak mixing angle, the differential distributions and decay angular coefficient in Drell-Yan events, W mass related observables, trilinear gauge-couplings and electroweak production of one and two vector bosons in associaton with two jets.
The production of multiple electroweak bosons at the LHC constitutes a stringent test of the electroweak sector and provide a model-independent means to search for new physics at the TeV scale. In this talk, we present recent results for inclusive WW, WZ, ZZ and Z$\gamma$ production in proton-proton collisions at $\sqrt s$ = 13 TeV collected by the ATLAS experiment. The data are sensitive to anomalous triple gauge couplings and are reinterpreted in terms of an effective field theory to constrain new physics beyond the Standard Model. In addition, the unfolded differential cross section for four-lepton production is presented and compared to state-of-the-art Standard Model calculations. Finally, evidence for the production of three massive vector bosons in WWW, WWZ and WZZ final states is presented.
The theory termed 'special relativity (SR) with a preferred frame' \cite{burde1, burde2} incorporates the preferred frame into special relativity while retaining the fundamental space-time symmetry which, in the standard SR, manifests itself as Lorentz invariance. In this paper, the theory is extended to particle dynamics and general relativity based on the concept of the 'modified spacetime symmetry' which allows to use the apparatus of the standard relativity but with properly transformed spacetime variables. To calculate physical effects, an inverse transformation to the 'physical' time and space intervals is applied.
On the basis of the extended particle dynamics the dispersion relation for free particles is derived. The modified dispersion relation is applied for calculating the
Greisen-Zatsepin-Kuzmin (GZK) limit due to the photopion production
in collisions of ultra high energy cosmic rays (UHECRs) off the cosmic microwave background (CMB) photons which, in the last years, is considered as providing a test of the validity of SR (see, e.g., \cite{A}). It is found that, in the particle dynamics of relativity with a privileged frame, a position of the GZK cutoff in the energy spectrum should depend on the distance to the source. This effect might be confirmed if the data could be sorted according to an event responsible for the UHECR's burst.
The modified general relativity (GR), like the standard GR, is based on
the equivalence principle but with the properly modified space-time local symmetry in which an invariant combination differs from the Minkowski interval of the standard SR.
Applying the modified GR to cosmology yields the luminosity distance -- redshift relation corrected such that the observed deceleration parameter can be negative as it is obtained from the data for type Ia supernovae. Thus,
the observed negative values of the deceleration parameter can be explained within the matter-dominated Friedman-Robertson-Walker cosmological model of the universe without introducing the dark energy.
A number of other observations, such as Baryon Acoustic Oscillations and Cosmic Microwave Background,
%that are commonly considered as supporting the late-time cosmic acceleration and the existence of dark energy,
also can be well fit to the cosmological model arising from the GR based on the SR with a privileged frame.
%\section*{References}
\begin{thebibliography}{99}
\bibitem{burde1} Burde G.I.,
%Special relativity kinematics with anisotropic propagation of light and correspondence principle.
Found. Phys. \textbf{46}, (2016) 1573
%--1597.
\bibitem{burde2} Burde G.I.,
%Special Relativity with a Preferred Frame and the Relativity Principle.
J. Mod. Phys.\textbf{9}, (2018) 1591
%--1616.
\bibitem{A} R. Aloisio et al.,
%Probing the structure of space-time with cosmic rays,
Phys.Rev. D62 (2000) 053010,
[astro-ph/0001258].
\end{thebibliography}
Dark Matter (DM) is one of the most puzzling mysteries of modern physics. Albeit various astronomical observations confirm its existence, no unambiguous theory of DM exists. CRESST-III is one of the leading experiments searching for a hypothetical DM particle candidate.
The CRESST-III experiment searches for direct interactions of dark matter with ordinary matter at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The main event signature would be a nuclear recoil inside one of the scintillating target crystals. Operating the crystals as cryogenic calorimeters at $\mathcal{O}(10\,\mathrm{mK})$ provides in addition a phonon signal as a measure of the deposited energy. The simultaneous readout of both a scintillation light and a phonon signal is used to actively discriminate backgrounds.
CRESST-III focuses on the sub-GeV/c² mass region where the sensitivity is driven by the threshold. With a $\mathrm{CaWO_4}$ crystal of 24g as target an unprecedented low threshold of 30.1eV for nuclear recoils was obtained in the first data taking campaign of CRESST-III from 2016-2018.
In this contribution, we briefly motivate the existence of DM and review the current landscape. Afterwards we will introduce CRESST, focusing on the requirements to maintain sensitivity in the sub-GeV/c² mass region. We will discuss the latest results of CRESST-III on spin-dependent and spin-independent interactions. Finally, we will give an outlook to future stages of CRESST.
The MAJORANA DEMONSTRATOR is a neutrinoless double-beta decay experiment currently operating two modules of p-type point contact germanium detectors at the 4850' level of the Sanford Underground Research Facility. Our latest results from 26 kg-yr of exposure set a half-life lower limit of 2.7 x $10^{25}$ yr (90% C.L) owing to an unprecedented energy resolution of 2.5 keV FWHM and a background rate of 12 cts/(FWHM t yr) at the $^{76}$Ge double-beta decay Q value of 2039 keV. Due to its low background rate, the DEMONSTRATOR’s physics data set has also been used to search for other physics beyond the Standard Model, including bosonic dark matter and tri-nucleon decay. Optimization of background-reducing analysis techniques and the development of a complete background model are expected to yield improved background rejection and to inform the design and background expectations of the next-generation LEGEND experiment. In this talk, I will review the key physics and technical results from the MAJORANA DEMONSTRATOR and report on progress in background reduction and modeling.
Measurements of the low masses for the pulsar PSR J0737-3039B, for the
companion of PSR J1756-2251 and for the companion of PSR J0453+1559 on the one
hand and of the high masses for the pulsars PSR J1614-2230 and PSR J0348-0432 on
the other demonstrate the existence of compact stars with masses in a broad range
from 1.2 to 2 Msun . We show that for realistic stellar matter EoS it is possible to explain the whole set of cooling data within "nuclear medium cooling" scenario for compact stars by a variation of the star masses. We select appropriate proton gap profiles from those exploited in the literature and allow for a variation of the effective pion gap controlling the efficiency of the medium modified Urca process.
Using the set of existing observational temperature-age data for neutron stars one can also extract their possible mass distribution from the cooling model, because for each of observed compact object its mass can be predicted from the model. Such analyses has been performed for a particular EoS - DD2 model and shown that indeed the interval of masses from 1.2 to 2 Msun should be equally populated.
We perform a Bayesian analysis for selecting the most probable equation of state under a set of constraints from compact star physics, which now include the tidal deformability from GW170817. It was considered a two-parameter family of hybrid equations of state, which produces a third family of hybrid stars in the mass-radius diagram. We present the corresponding results for compact star properties like mass, radius and tidal deformabilities and use empirical data for them in Bayesian analysis method to obtain the probabilities for the model parameters within their considered range.
Classical and quantum dynamics of higher derivative systems
I will briefly present the main ideas of the Generalized Uncertainty Principle (GUP) and the Extended Uncertainty Principle (EUP). Then, first I will discuss the impact of GUP onto the Bekenstein entropy and the Hawking temperature and show how GUP influences the Hawking radiation leaving a remnant of a radiating black hole. I will also show that when GUP is applied, the Hawking radiation does not necessarily have to be sparse when a black hole approaches the Planck mass. Finally, I will present the influence of EUP on the Bekenstein entropy and the Hawking radiation for Rindler and cosmological spacetimes. Some interesting relations between black hole thermodynamics and the principle of maximum tension will also be uncovered.
Deviations of R^2 cosmology from the Einstein's General Relativity
Inflation can explain why the Universe is flat and homogeneous at large scales. However, it is not falsifiable unless also responsible for the matter perturbations sourcing the cosmic structure formation and anisotropy of cosmic microwave background. Moreover, even in that case different models often give (almost) the same predictions for the cosmological spectra, and it would be nice to test these inflationary models in other ways. The Higgs inflation is one of the examples naturally providing with such independent tests. A recently suggested modification with $R^2$-term solves the strong coupling problem in the original Higgs inflation allowing for perturbative matching of high-energy and low-energy model coupling constants, which is required to perform such direct tests. A remarkable feature of the model is instant preheating due to tachyonic instabilities in Higgs and vector boson sectors, which ask for a special study.
Phase transitions can occur in string theory, when the scale of spontaneous breaking of supersymmetry is of the order of the string scale. We describe these instabilities at the level of the effective supergravity at low energy. In this framework, infinitely many scalars that can become tachyonic are taken into account. They play the role of order parameters whose condensations yield various phases, with drastically different properties.
TBA
A new project named NICA (Nuclotron-based Ion Collider facility) is under realization at JINR. The main NICA scientific goal is the experimental exploration of yet poorly known region of the QCD phase diagram of high baryon density. Of particular interest is the strange sector of the phase diagram, which can be probed with multiple hadron specie (from kaons to multistrange hyperons) and hypernuclei. The MultiPurpose Detector (MPD) at NICA is a high-resolution device providing precise reconstruction of heavy-ion collisions and measure of the production of charged and neutral kaons, hyperons, nuclear clusters, and hypernuclei [2].
In my report physics motivation for the study of strangeness and hypernucler production at NICA will be given together with the model predictions for the estimated particle production yields. The latter will be supported with the first results of feasibility study for hyperon and hypernuclear reconstruction with the MPD detector
The completion of the construction of the ESFRI landmark FAIR is the highest priority of the NuPECC Long Range Plan on the perspectives in Nuclear Physics.
The realization of the Facility for Antiproton and Ion Research at Darmstadt, Germany has advanced significantly. The civil construction the Northern part of the building complex, including the SIS100 synchrotron tunnel is progressing well.
On site, at the GSI campus the upgrade of the existing accelerators, which will serve as injector chain for FAIR, has been completed. The series production of the components of the FAIR accelerator complex is ongoing. A large number of the superconducting SIS100 magnets has been produced and is accepted already. Major testing infrastructures for superconducting magnets have been set-up. The procurement of the components of all other FAIR accelerator systems is progressing well.
Also the construction of the experiment detector systems of the four research pillars of FAIR, APPA, CBM, NUSTAR and PANDA is ongoing. The schedule foresees the start of operation of the FAIR experiments in 2025.
Meanwhile the FAIR-Phase-0 experimental programme e.g. with the upgrades HADES detector is producing exciting data.
The progress of the realization of the FAIR facility and the prospects of its science will be presented.
TBA
The exploration of the phase diagram of strongly interacting matter is one of the most challenging fields of modern high-energy physics. The major challenge is to find diagnostic probes which are connected to chiral symmetry restoration and to the related phase transition. Very promising observables are short-lived vector mesons decaying into dilepton pairs inside the fireball. Since leptons are essentially unaffected by the passage through the high-density matter, they provide almost undistorted information on the conditions in the interior of the collision zone.
In order to reduce the systematic uncertainties of the very challenging dilepton measurements, the CBM experiment is equipped with electron and muon detectors. Electrons will be identified by a Ring Imaging Cherenkov (RICH) detector together with a Transition Radiation Detector (TRD), which are located between the Silicon Tracking System (STS) and the Time-of-Flight (TOF) detector. This setup allows the simultaneous identification of hadrons and electrons. For muon measurements, the RICH will be replaced a Muon-Chamber (MuCh) System which consists of several hadron absorbers sandwiched by GEM tracking stations. The modular setup allows the identification of muons with a high signal-to-background ratio over the full FAIR beam energy range. Although most of the hadrons will be absorbed in the MuCh, the hadrons, which penetrate the absorbers, can be identified and used for the physics analysis. First simulation results of simultaneous muon and hadron identification will be presented.
LHCb collaboration has been pioneering the employment of machine learning in real-time
computing, related to the high energy physic field (HEP), since 2015. The LHCb software trigger exploited a novel machine learning techniques based on binned boosted decision tree model that helped to select high-quality physics data in real-time. After that, a major modernisation of the algorithms for tracking, particle identification and offline physics selections using computing intelligence followed. Especially huge improvements of the background rejection factors for numerous physics analyses led to using the multivariate techniques as a standard step in obtaining clean signals within LHCb collaboration. In this presentation, we give a short overview of the tools and techniques based on the machine learning approach by LHCb experiment. We address the issues related to the proper selection of the training and verification data sets that are vital for the final results. One of the critical issues is to keep up with the rapid development of the tools, libraries and new ideas from outside of the HEP domain (mainly based on the ROOT package). Application of third-party software will be discussed through the application of a long-lived particles tracking algorithm that was commissioned and successfully operated during the second data taking a period of the LHCb experiment.
The LHC accelerator and experiments program have lead to rediscovering the Standard Model (SM) in the first months of data taking.
Machine learning techniques have been instrumental to the discovery of the Higgs boson in 2012, and have become crucial in the following era.
On one side precision measurements require precise calibrations, on the other searches for rare SM processes and for beyond-SM processes require sifting to a huge amount of data in search for a very small signal. With these objectives, state-of-the-art machine learning techniques are being applied already.
The ongoing upgrade of the detectors in preparation of Run III also requires data acquisition systems to be prepared for very noisy data; studies for the integration of machine learning techniques in such systems (e.g. trigger), also in hardware-embedded form, are ongoing.
In this talk I will review the use of Machine Learning tools at the LHC, providing a state-of-the-art picture of the topic.
Current status of wormholes in generalized Galileon theories
Stability and superluminality of cosmological models in generalized Galileon theories
An interesting direction beyond the standard model predicts additional
gauge bosons with double electric charge which decay into like-sign
charged lepton pairs. Such a model explains the occurrence of
exactly three quark-lepton families when we insist on QCD asymptotic
freedom. The bileptons are predicted to have mass between 800 GeV
and 2 TeV a mass range accessible to data already in the LHC cloud.
CMS Top Physics Highlights
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay (0νββ) that has been able to reach the one-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. The CUORE data-taking began in Spring 2017 and, from examining a total TeO2 exposure of 86.3 kg∙yr, characterized by an average energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/(keV∙kg∙yr), CUORE was able to place the current best lower limit on the 130Te 0νββ half-life of > 1.3 × 10^25 yr (90% C.L.). After some improvements in the detector performance achieved in 2018 and a period of cryogenic and technical maintenance, CUORE is back to stable data taking since Spring 2019. In this talk we will discuss the status, recent results and future outlook of CUORE.
SoLid is a very short baseline reactor neutrino oscillation experiment. The goal of the experiment is to test the sterile neutrino hypothesis and to measure the BR2 reactor antineutrino spectrum of pure $^{235}$U with high precision. Operation of detector on the surface and very close to the research reactor core requires handling the high levels of background induced by the reactor and cosmic rays. SoLid has a unique take on those measurements; it uses an innovative highly segmented solid scintillation technology, combining PVT (cubes of 5×5×5 cm$^3$ ) and $^6$LiF:ZnS (sheets $\sim 250 \mu$m thickness) scintillators. This combination provides a linear energy response with good resolution and unprecedented spatial and time reconstruction of antineutrino interactions. The detector system is highly segmented, read out by a network of wavelength shifting fibers and SiPMs with an intelligent triggering scheme that records real time data with high efficiency. The detector has been taking physics data for almost a year in the BR2 reactor area. We will present an overview of the experiment, the detailed features of antineutrino reconstruction in SoLid, the calibration methods, background rejection capabilities and some preliminary analysis of the antineutrino data.
Recently the MiniBooNE collaboration observed electron (anti)neutrino appearance in the muon (anti)neutrino beams. The significance of the effect reaches 6.0σ level when combined with the LSND result. Even more recently the NEUTRINO-4 collaboration claimed the observation of electron antineutrino oscillations to sterile neutrinos with a significance of about 3σ. If these results are confirmed, New Physics beyond the Standard Model would be required.
On the other hand, the DANSS experiment and several other reactor experiments at short baselines obtained quite strict limits on the hypothetical sterile neutrino parameters. We present new results of the DANSS experiment on the searches for sterile neutrinos. They are based on more than 2 million of inverse beta decay events collected at 10.7, 11.7 and 12.7 meters from the reactor core of the 3.1 GW Kalinin Nuclear Power Plant in Russia. This data sample is 2.4 times larger than the data sample in the previous DANSS publication. The neutrino spectrum dependence on the fuel composition is also presented. We have also measured the reactor power using the IBD event rate during 17 months with the statistical accuracy 1.5% in 2 days and with the relative systematic uncertainty of about 0.5%.
The advent of quantum theory of information stimulated investigations across traditional frontiers. Among others we are witnessing an extension of quantum information notions into the general relativity framework. As a consequence entanglement, being recognized as a fundamental resource in quantum information processing, has been widely investigated in curved spacetime. In particular it has been realized the possibility of generating it by the expansion of universe. This effect can be traced back to the mechanism of particle-antiparticle production during cosmic evolution. The vast majority of studies along this line focus on homogeneous and isotropic spacetime, that is, using a Friedman-Robertson-Walker (FRW) background. However our universe is neither homogeneous nor isotropic: there are structures in it, galaxies, clusters of galaxies, super-clusters, etc. which causes deviations of the FWR background. Even in the very early universe one expects quantum fluctuations from this FWR background to occur. Then an interesting question is if we could in principle observe by means of particle correlations any departure from homogeneity and isotropy. Thus we want at least partially release the symmetry assumptions for the metric and consider anisotropy, i.e. a metric whose space part depends the direction. Dealing with anisotropic spacetime models present technical difficulties and solutions can only be pursued by resorting to perturbative approaches. In this way entanglement for the scalar field has been recently studied by us in the anisotropic spacetime context. Here we present an enlarged study that encompasses also the Dirac field and provides a comparison between the two cases (spin-less and spin-1/2 field). We found there marked differences between scalar and Dirac fields for the massive case and similarities for the massless case. In fact, while for massive scalar field revivals of entanglement entropy vs momentum appear after decreasing from the maximum at k = 0, in the massive Dirac field we find just a slight distortion of the non-monotonic profile giving rise to the maximum of entanglement entropy at k > 0. In contrast, it turns out that massless field of both type can only get entangled through anisotropy, with a maximum of entanglement entropy occurring at k > 0.
Optimally encoding classical information in a quantum system is one of the oldest and most fundamental challenges of quantum information theory. Holevo's bound places a hard upper limit on such encodings, while the Holevo-Schumacher-Westmoreland (HSW) theorem addresses the question of how many classical messages can be "packed" into a given quantum system. In this article, we use Sen's recent quantum joint typicality results to prove a one-shot multiparty quantum packing lemma generalizing the HSW theorem. The lemma is designed to be easily applicable in many network communication scenarios. As an illustration, we use it to straightforwardly obtain quantum generalizations of well-known classical coding schemes for the relay channel: multihop, coherent multihop, decode-forward, and partial decode-forward. We provide both finite blocklength and asymptotic results, the latter matching existing formulas. Given the key role of the classical packing lemma in network information theory, our packing lemma should help open the field to direct quantum generalization.
Forward hadron calorimeters with transverse and longitudinal segmentation are developed for upgraded heavy ion NA61/SHINE, BM@N experiments and future CBM experiment at FAIR. The main purpose of these calorimeters is to provide an experimental event-by-event measurements of the centrality and orientation of reaction plane in heavy-ion collisions at high beam rates. One of the features of these modular calorimeters is the presence of a beam hole in the centre, which is necessary for the operation at high beam rates. Hadron calorimeters in all of these experiments are composed of sampling lead/scintillator modules with longitudinal segmentation. Light collection in the modules is provided by WLS fibers embedded in grooves in the scintillator plates. The light from 6 consecutive scintillator plates in the module (section) is collected together and is detected by one Hamamatsu MPPCs with an active area of 3x3mm2 placed at the end of module. The light yield measured with muons beam is about 40-50 ph.e./section. The response of supermodule (array 3x3 assembled from 9 CBM modules) has been studied on CERN T9, T10 and NA61/SHINE proton beams in the energy range 1.5-150 GeV. The features of the calorimeters operation in NA61/SHINE, BM@N and CBM experiments, results of the measured response of the supermodule and expected radiation conditions simulated for these calorimeters will be presented.
The PANDA experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt/Germany aims to investigate fundamental questions of hadron physics. PANDA is designed as a fixed target experiment for an antiproton beam with a momentum range of 1.5 GeV/c to 15 GeV/c. In order to obtain an excellent particle identification of pions and kaons, two independent DIRC detectors have been developed for two adjacent spatial regions. The Barrel DIRC covers polar angles from 22°-140° and performs π/K separation with 3 σ or more for momenta from 0.5 to 3.5 GeV/c. The novel Endcap Disc DIRC (EDD) detector will cover the forward polar angles between 5° and 22° and will provide a π/K separation up to 4 GeV/c with a separation power of ≥ 3 σ. The design of the Barrel DIRC is based on the successful BaBar DIRC and the SuperB FDIRC R&D with several improvements to optimize the performance for PANDA. Both PANDA DIRC detectors use synthetic fused silica as material for radiators and lightguides and lifetime-enhance Microchannel Plate PMTs (MCP-PMTs) as sensors. The Barrel DIRC uses narrow bars as radiator, a prism-shaped expansion volume and a complex multi-layer spherical lens as focusing system. The Cherenkov radiator for the EDD is a large, 2 cm thick fused silica plate that is divided into 4 identical quadrants. A combination of bars and cylindrical elements with aluminum coating focus the Cherenkov light on the MCP-PMTs with segmented anode plates.
The technical design of the two DIRC detectors and the performance of prototypes tested in a mixed hadron beam at CERN will be presented.
Universal gate design with beamsplitters and phase shifters
The Bell's theorem stands as an insuperable roadblock in the path to a very desired intuitive solution of the Einstein-Podolsky-Rosen paradox and, hence, it lies at the core of the current lack of a clear interpretation of the quantum formalism. The theorem states through an experimentally testable inequality that the predictions of quantum mechanics for the Bell's polarization states of two entangled particles cannot be reproduced by any statistical model of hidden variables that shares certain intuitive features. In this paper we show, however, that the proof of the Bell's inequality involves a subtle, though crucial, assumption that is not required by fundamental physical principles and, moreover, it might not be fulfilled in the experimental setup that tests the inequality. In fact, this assumption can neither be properly implemented within the framework of quantum mechanics. Namely, the proof of the Bell's theorem assumes that there exists an absolute preferred frame of reference, supposedly provided by the lab, which enables to compare the orientation of the polarization measurement devices for successive realizations of the experiment. The need for this assumption can be readily checked by noticing that the theorem does not hold when the orientation of one of the detectors is taken as a reference frame to define the relative orientation of the second detector, in spite that this frame is an absolutely legitimate choice according to Galileo's principle of relativity. We further notice that the absolute frame of reference required by the proof of the Bell's theorem cannot exist in models in which the hidden configuration of the pair of entangled particles has a randomly set preferred direction that spontaneously breaks the global rotational symmetry. In fact, following this observation we build an explicit local model of hidden variables that reproduces the predictions of quantum mechanics for the Bell's states.