Publications

Order by: publication date number of citations

• TMD observables in unpolarised Semi-Inclusive DIS at COMPASS

  Andrea Moretti

  SciPost Phys. Proc. 8, 144 (2022) · published 14 July 2022 | Toggle abstract · pdf

  In 2016 and 2017, the COMPASS Collaboration at CERN collected a large sample of DIS events with a longitudinally polarised 160 GeV/$c$ muon beam scattering off a liquid hydrogen target. Part of the collected data has been analysed to extract preliminary results for the amplitudes of the modulations in the azimuthal angle of the charged hadrons and for their transverse-momentum distributions. These observables give relevant information for the study of the transverse momentum and spin structure of the nucleon. Similarly to the results obtained in COMPASS with a deuteron target, the azimuthal asymmetries exhibit interesting kinematic dependences, while the squared-transverse-momentum distributions can be described by two exponentials.

  1 citation

• Measurements of $W$ and $Z/γ^*$ cross sections and their ratios in $pp$ collisions at STAR

  Jae Nam

  SciPost Phys. Proc. 8, 140 (2022) · published 14 July 2022 | Toggle abstract · pdf

  While the unpolarized parton distribution functions of the valence quarks ($d$ and $u$) are well determined from DIS experiments, the sea quark counterparts, $\bar{d}$ and $\bar{u}$, are much less constrained, in particular, near the valence region. Measurements of $W^+/W^-$ production ratio in $pp$ collider experiments, such as the STAR experiment at RHIC, can probe the $\bar{d}/\bar{u}$ ratio at a large $Q^2$ set by the $W$ mass. These proceedings will discuss recent results of $W$ and $Z$ cross-section measurements using the STAR $pp$ collision data at a center-of-mass energy of $\sqrt{s} = 500/510\;\mathrm{GeV}$ collected in 2011, 2012, 2013 and 2017.

• Comparison of $pp$ and $p \bar{p}$ differential elastic cross sections and observation of the exchange of a colorless $C$-odd gluonic compound

  C. Royon

  SciPost Phys. Proc. 8, 138 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We describe the discovery of the colorless $C$-odd gluonic compound, the odderon, by the D0 and TOTEM Collaborations by comparing elastic differential cross sections in $pp$ and $p \bar{p}$ interactions at high energies.

• Particle Physics with the Pierre Auger Observatory

  Matias Perlin

  SciPost Phys. Proc. 8, 130 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The Pierre Auger Observatory is the largest extensive air shower detector. Based on a hybrid system, this experiment measures the longitudinal shower development and the particles at the ground. This detection system allows the extraction of the p-air cross-section at energies much higher than the ones accessible by current colliders. It is also possible to test hadronic interaction models using correlations between different air shower observables, like the depth of shower maximum and the muon number at the ground and their fluctuations. Thanks to the low energy extension of the Pierre Auger Observatory, the muon deficit in air shower simulations can be addressed over almost three decades at the highest energies.

  2 citations

• Physics motivation and detector upgrades for the new era of the ATLAS experiment

  Jason Nielsen

  SciPost Phys. Proc. 8, 126 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The ATLAS experiment at CERN’s Large Hadron Collider (LHC) will be upgraded in two stages to prepare first for the Run 3 data-taking campaign, during which the integrated luminosity will roughly double, and then for the High-Luminosity LHC program with an ultimate integrated luminosity of up to 4 ab-1. These upgrades and high-statistics datasets will allow ATLAS to perform searches and precision measurements to constrain the Standard Model in yet-unexplored phase spaces and in the Higgs sector. This contribution summarizes the ATLAS detector upgrades and selected physics prospects for Run 3 and the HL-LHC.

• Longitudinal and Transverse Spin Transfer of $Λ$ and $\overlineΛ$ Hyperons in Polarized $p$+$p$ Collisions at $\sqrt{s} = 200$ GeV at RHIC-STAR

  Yike Xu

  SciPost Phys. Proc. 8, 125 (2022) · published 13 July 2022 | Toggle abstract · pdf

  Measurements of the longitudinal spin transfer, $D_{LL}$, and the transverse spin transfer, $D_{TT}$, of the $\Lambda(\bar{\Lambda}$) hyperon in polarized $p$+$p$ collisions are expected to be sensitive to the helicity distribution and transversity distribution of the $s(\bar{s})$ quark in proton and the corresponding polarized fragmentation functions. This contribution presents the new preliminary results of the $\Lambda(\bar{\Lambda}$) $D_{LL}$ and $D_{TT}$ using data collected at RHIC-STAR experiment in 2015, with twice larger statistics than previously published results.

• Recent results on top quark mass and properties and rare/anomalous top quarks interactions in CMS

  Sebastian Wuchterl

  SciPost Phys. Proc. 8, 120 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The amount of data collected by the CMS experiment at the CERN LHC in the second data taking period provides the possibility to study absolute and differential cross sections of top quark interaction processes with high precision. Utilizing these results, fundamental standard model parameters such as the top quark mass are extracted. Moreover, given standard model measurements are interpreted in the context of Beyond the standard model theories. Recent results on top quark properties and rare or anomalous top quark interactions by CMS are presented in these proceedings. Furthermore, the implications of experimental results to effective field theory are discussed.

• Prospects for Higgs and di-Higgs measurements at the ATLAS experiment

  Alessandra Betti

  SciPost Phys. Proc. 8, 117 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The large dataset of about 3000 $\rm{fb}^{-1}$ that will be collected at the High Luminosity LHC (HL-LHC) will be used to measure Higgs boson processes in detail. This large dataset will also provide sensitivity to di-Higgs processes and will allow for the improvement of the constraints on the Higgs boson self coupling. Studies based on current ATLAS analyses using LHC Run 2 data have been carried out to understand the expected precision and limitations of the Higgs and di-Higgs measurements at the HL-LHC. This paper presents the ATLAS prospects for Higgs and di-Higgs results at the HL-LHC.

• Measurement of the $t\bar{t}t\bar{t}$ production at 13 TeV with the ATLAS detector at the LHC

  Ö. Ogul Öncel

  SciPost Phys. Proc. 8, 116 (2022) · published 13 July 2022 | Toggle abstract · pdf

  Two measurements and their combination for the $t\bar{t}t\bar{t}$ production cross-section analysis using 139 fb$^{-1}$ of proton$-$proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the LHC are presented. The first analysis uses the final states with either one or two opposite-sign leptons (electrons or muons). In the second analysis the final states with either two same-sign or at least three leptons are considered. With an observed (expected) significance of 4.3 (2.4) standard deviations over the background-only hypothesis, the second analysis provides the first evidence for the $t\bar{t}t\bar{t}$ process. No significant deviations from the Standard Model are observed.

• Measurements of $t\overline{t}$ production cross-sections with the ATLAS experiment at the LHC

  Margherita Spalla

  SciPost Phys. Proc. 8, 112 (2022) · published 13 July 2022 | Toggle abstract · pdf

  Comprehensive measurements of differential cross-sections of top-quark-antiquark pair-production are presented. They are performed in the dilepton, lepton+jets and the all-hadronic channels, using $\sqrt{s}=13$ TeV data from the ATLAS detector at the LHC. Several setups of next-to-leading order and next-to-next-to-leading order generators are quantitatively compared to the measurements. In addition, total cross-section measurements using up to the full ATLAS Run 2 dataset are presented.