The ATLAS New Small Wheels (NSW) Phase I Muon System upgrade will use Micromegas and small-strip Thin Gap Chambers (sTGC) as both trigger and precision tracking detectors. A new ASIC, the VMM, is being developed for the front end of both detector technologies. The VMM is a sophisticated ASIC, System on Chip (SOC), providing digitized amplitude and time information as well as independent...
The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at
centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 10^34 cm−2 s−1 . Liquid argon (LAr)
sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2,
and for hadronic calorimetry in the region from |η| = 1.5 to |η| =...
The ATLAS experiment at the LHC is planning a second phase of upgrades to prepare for the "High
Luminosity LHC", a 4th major run due to start in 2026. In order to deliver an order of magnitude more data than
previous runs, 14 TeV protons will collide with an instantaneous luminosity of 7.5 × 1034 cm−2s−1, resulting
in much higher pileup and data rates than the current experiment was...
The measurement of Higgs pair production will be a cornerstone of the LHC program in the coming years. Double Higgs production provides a crucial window upon the mechanism of electroweak symmetry breaking and has a unique sensitivity to the Higgs trilinear coupling. We study the feasibility of a measurement of Higgs pair production in the bbbb final state at the LHC. Our analysis is based on a...
In recent years, micropattern gaseous detectors received significant attention in the development of precision and cost-effective tracking detectors in nuclear and high energy physics experiments. The important task for these detectors is not only a precise position measurement, but also the determination of the incoming angle of traversing particles in high rate environments, present for...
Large size resistive Micromegas (MM) detectors will be employed for the first time in high-energy physics experiments for the Phase I upgrade of the ATLAS Muon Spectrometer at the LHC. The current innermost stations of the muon end-cap system, the Small Wheel, will be upgraded to retain the good precision tracking and trigger capabilities in the high background environment expected with the...
The Drell-Yan (DY) process stands for a unique probe to testing initial-state effects that is not accompanied with any final state interaction, either energy loss or absorption. Moreover, the measured DY dilepton pair mass allows to investigate different kinematical regions where coherence or non-coherent effects are expected only. For this purpose, we used the color dipole approach where for...
We present the calculation of the NLO QCD corrections to the electroweak production of top-antitop pairs at the CERN LHC in the presence of a new neutral gauge boson. The corrections are implemented in the parton shower Monte Carlo program POWHEG. Standard Model (SM) and new physics interference effects are properly taken into account. QED singularities, first appearing at this order, are...
In this work one investigates the LHC potential for discovering doubly-charged vector bileptons considering the measurable process p,p → μ+,μ+,μ-,μ-,X. We perform the study assuming different bilepton masses and different exotics quark masses. The process cross-section is calculated at leading-order using the CALCHEP package. Combining this calculation with the latest ATLAS results at 8 TeV,...
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We investigate the renormalization group running of gauge couplings in various radiative neutrino mass models, which generate neutrino masses at one- and two-loop order. We discuss the possibility for these couplings to unify in such models at an energy scale close to the GUT scale. The studies are performed both analytically, at one-loop level, and numerically, at two-loop level, using the...
We present measurements of the differential production cross section of B hadron in pp collisions at a center-of-mass energy of 13 TeV. The data sample used in this study was collected by the CMS experiment in 2015 , with a bunch spacing of 25ns, it corresponds to an integrated luminosity of 2.71 fb-1. These measurements are important tools to investigate heavy-quark production mechanisms in QCD.
The lack of conclusive evidence for new physics in Run I of the LHC suggests that future discoveries may manifest themselves with small numbers of signal events. In this case, it will be crucial to use analysis techniques that extract as much information as possible from a limited number of events. Previously, a technique exploiting correlations in the full multi-particle phase space to...
Differential and integrated fiducial cross sections measured using the $\rm H \to \rm W^+W^-$ leptonic decays, are presented as a function of the Higgs boson production. The measurements are performed using pp collisions at a centre-of-mass energy of $8~\rm TeV$ collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of $19.4~\rm fb^{-1}$. The Higgs boson...
The main aim of the LHC forward (LHCf) experiment is to provide precise measurements of the
particles production spectra in the forward region. These calibration data are very important for the tuning of hadronic interaction models used by ground-based cosmic rays experiments. LHC is the most suitable place where we can perform these measurements because proton-proton collisions at $\sqrt{s}$...
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In the previous efforts, we constructed N-Body systems based on non-temporal and nonlinear extension of Lorentz transformation. In this construction, we rely only on two parameters, nonlinear degree and normalized momentum to characterize the systems. We then explored root computation via iteration in the context of dynamical systems. The solution sets demonstrate various forms similar to...
We investigate the questions connected with the possible anomalous magnetic moment of the Higgs boson at a mass around 125 GeV discovered at the LHC ATLAS and CMS experiments. We have derived a simple analytical formula for the anomalous magnetic moment of the Higgs boson in a sufficiently strong magnetic field. We have performed numerical estimations on the anomalous magnetic moment of the...
The Missing Transverse Energy is a key observable in many CMS searches for Physics Beyond Standard Model. A detailed and precise understanding of this quantity is required to accomplish the CMS Physics program, while the high collision rate at the CMS detector during the 13 TeV data-taking periods of the LHC poses challenges to reconstruction far beyond those previously overcome.
This poster...
The Tile Calorimeter (TileCal) of the ATLAS experiment at the LHC is the central hadronic calorimeter designed
for energy reconstruction of hadrons, jets, tau-particles and missing transverse energy. TileCal is a
scintillator-steel sampling calorimeter and it covers the region of pseudorapidity < 1.7. The scintillation l
ight produced in the scintillator tiles is transmitted by wavelength...
In this poster, results of the Phase1 upgrade of the CMS Hadron Calorimeter (HF) will be discussed. The CMS-HF Calorimeter was using regular PMTs. Cherenkov light produced in the fibers embedded in the absorber was read out with the PMTs. However, occasionally stray muons hitting the PMT windows cause Cherenkov radiation in the PMT itself and produce large signals. These large signals mimic a...
The ATLAS trigger system aims at reducing the 40 MHz protons collision event rate to a
manageable event storage
rate of 1 kHz, preserving events with valuable physics
meaning. The Level-1 trigger is the first rate-reducing
step in the ATLAS
trigger system, with an output rate of 100 kHz and decision latency of less
than 2.5 micro
seconds. It is composed of the calorimeter trigger,...
We study the sensitivity of top pair production and six-fermion decay at the LHC to the presence and nature of an underlying Z' boson, accounting for full tree-level Standard Model interference, with all intermediate particles allowed off-shell. We concentrate on the lepton-plus-jets final state and simulate experimental considerations, including kinematic requirements and top quark pair...
In this work, we present a trinification-based Grand Unified Theory (GUT) incorporating a global SU(3) flavour symmetry that after a spontaneous breaking leads to a Left-Right (LR) symmetric model. Already at the classical level, this model can accommodate the matter content and the quark Cabbibo mixing in the Standard Model (SM) with only one Yukawa coupling at the unification scale....
The forward muon system of the CMS experiment is comprised of about 500 Cathode Strip Chambers (CSCs) with the total sensitive area of 6000 square meters. In view of the operating conditions at High Luminosity LHC (HL-LHC), it is vital to assess the CSC system performance in terms of their ability to operate in the expected HL-LHC instantaneous rates and in terms of their longevity over the...
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Presented are the results of the CMS search for a neutral Higgs boson in the mass range above 200 GeV in pp collisions at 8 TeV and 13 TeV center of mass energy
A search for new physics is performed using events having large missing transverse momentum and one or more jets with high transverse momenta in a data sample of proton-proton interactions at the centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 2.3 fb − 1 collected in 2015 by the CMS detector, during the Run2 of the LHC. Results are presented in terms of...
A search for electroweak production of supersymmetric particles is performed with two tau leptons in the final state. These results are based on 18.1 to 19.6 fb-1 of proton- proton collisions at $\sqrt{s}$ = 8 TeV, collected with the CMS detector at the CERN Large Hadron Collider. The observed events are found to be consistent with the standard model prediction. Upper limits are set on the...
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A search for a new narrow resonance decaying to an electron pair or a muon pair is performed using 13 TeV pp collision data collected by the CMS experiment at the CERN LHC. The electron event sample used corresponds to an integrated luminosity of 2.6 fb−1 while the muon event sample used corresponds to an integrated luminosity of 2.8 fb−1. The results are interpreted in terms of the possibile...
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A search for new physics in the high mass ditau final state is performed using pp collisions at 13 TeV. The data used was collected by the CMS experiment during 2015 with an integrated luminosity of 2.3 fb-1. Results are interpreted considering a number of theoretical models such as Z', large extra dimension scenario, R-parity violating theories.
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A search for the standard model Higgs boson is presented in the Vector Boson Fusion production channel with decay to bottom quarks. A data sample comprising 2.2 fb^−1 of proton-proton collision at sqrt(s) = 13 TeV collected during the 2015 running period has been analyzed. Production upper limits at 95% Confidence Level are derived for a Higgs boson mass of 125 GeV, as well as the fitted...
We present a search for new massive particles decaying to a pair of top quarks with the CMS detector at the LHC. Proton-proton collision data recorded at a centre-of-mass energy of 13 TeV are used. The search is performed by measuring the invariant mass distribution of the top-quark pair and testing for deviations from the expected Standard Model background. Final states with 0 or 1 leptons...
A search for the standard model Higgs boson produced in association with a top quark pair is presented, using 2.3 /fb of 13 TeV pp collision data collected by the CMS experiment at the CERN LHC. Final states with a Higgs boson that decays to either ZZ,WW, or ττ are required to have a top quark pair that decays to either lepton plus jets (tt → lνjjbb) or dileptons (tt → lνlνbb), where l...
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Studies of Higgs boson production using the H->ZZ->4l decay channel are performed using a data sample corresponding to an integrated luminosity of 2.8 fb-1 of pp collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the LHC during 2015. The observed significance for the standard model Higgs boson with mH = 125.09 GeV is 2.5sigma, where the expected significance is...
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A search is presented for physics beyond the standard model in final states with two opposite-sign same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 2.2 inverse fb of proton-proton collisions at sqrt{s}=13 TeV collected with the CMS detector at the CERN LHC in 2015. The analysis focuses on the invariant mass distribution of...
ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require
high resolution, unbiased measurement of all charged particle kinematic parameters. These critically
depend on the layout and performance of the tracking system and the quality of its offline alignment.
For the LHC Run II, the system has been upgraded with the installation of a new
pixel layer,...
The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. During Run II, the LHC will increase its centre-of-mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2e34cm-2s-1. In order to guarantee a successful and ambitious physics programme under this intense...
The high-luminosity upgrade of the LHC will increase the rate of the proton-proton collisions by
approximately a factor of 5 with respect to the initial LHC design. The ATLAS experiment will upgrade
consequently, increasing its robustness and selectivity in the expected high radiation environment.
In particular, the earliest, hardware based, ATLAS trigger stage (“Level 1") will require...
We develop a very first model to describe the energy dependence of the tetraquark production cross section in proton-proton collisions. The model implements a mixture of two different formalisms. It uses the Double Parton Scattering (DPS) to describe the production of two quark pairs (a $q_1\bar{q}_1$ plus a $q_2\bar{q}_2$) and uses the Color Evaporation Model (CEM) to describe the coalescence...
The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger, a streamlined version of the CMS offline reconstruction software running on a computer farm. In this poster we will present the performance with the specific algorithms developed to cope with the increasing LHC pile-up and bunch...
The upgrade of the LHCb experiment will operate at an instantaneous luminosity of 2x10^33 cm^-2 s^-1 with a fully software based trigger, allowing to read out the detector at a rate of 40MHz. The tracking system will be redesigned: the vertex locator (VELO) will be replaced by a pixel-based detector, upstream of the magnet, a silicon mico-strip detector with a high granularity and an improved...
Hadronic signatures are from the most promising in the high energy physics analysis program, broadly
used for both Standard Model measurements and searches for new physics. These signatures include generic quark
and gluon jets as well as jets originating from b-quarks or tau leptons decaying hadronically. Additionally
missing transverse momentum from non-interacting particles provide an...
The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS detector
at the LHC. It is a sampling calorimeter consisting of alternating thin steel plates and scintillating tiles.
Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier
tubes. An analog sum of the processed signal of several...
The exclusive vector meson production in photon - induced interactions at LHC is investigated using the color dipole formalism and considering different models for the vector wave functions and forward dipole - target scattering amplitude. Our goal is to update the color dipole predictions and estimate the theoretical uncertainty present in these predictions. We present predictions for the...
Discover modern physics through art - discover art through modern physics
Illustrating some physics milestones from 1915 (Karl Schwarzschild) to2012 (the discovery of the Higgs particle).
Paper submitted 13-04-2016 by Linda Jarlskog and Stefan Agnani, Dalby, Sweden*, and Ulf Söderstrand, Anderslöv, Sweden
![enter image description here][1]
*http://www.artandscience.se/
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