Measurements of the suppression and correlations of dijets in Xe+Xe collisions at $\sqrt{s_{NN}}$ = 5.44 TeV

Abstract

Measurements of the suppression and correlations of dijets is performed using 3 $\mu$b${}^{-1}$ of Xe+Xe data at $\sqrt{s_{\mathrm{NN}}}=5.44$ TeV collected with the ATLAS detector at the LHC. Dijets with jets reconstructed using the $R=0.4$ anti-$k_t$ algorithm are measured differentially in jet $p_{\text{T}}$ over the range of 32 GeV to 398 GeV and the centrality of the collisions. Significant dijet momentum imbalance is found in the most central Xe+Xe collisions, which decreases in more peripheral collisions. Results from the measurement of per-pair normalized and absolutely normalized dijet $p_{\text{T}}$ balance are compared with previous Pb+Pb measurements at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. The differences between the dijet suppression in Xe+Xe and Pb+Pb are further quantified by the ratio of pair nuclear-modification factors. The results are found to be consistent with those measured in Pb+Pb data when compared in classes of the same event activity and when taking into account the difference between the center-of-mass energies of the initial parton scattering process in Xe+Xe and Pb+Pb collisions. These results should provide input for a better understanding of the role of energy density, system size, path length, and fluctuations in the parton energy loss.

40 pages in total, 8 figures, 3 tables, author list starting in page 23, published in PRC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2018-28/

References in corpus (11)

• An Introduction to PYTHIA 8.2
• Herwig++ Physics and Manual
• Glauber Modeling in High Energy Nuclear Collisions
• Jet energy measurement and its systematic uncertainty in proton-proton collisions at $\sqrt{s}=7$ TeV with the ATLAS detector
• Colour reconnections in Herwig++
• Measurements of the Nuclear Modification Factor for Jets in Pb+Pb Collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the ATLAS Detector
• Measurements of inclusive jet spectra in pp and central Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Progress in the Glauber model at collider energies
• Determination of jet calibration and energy resolution in proton-proton collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector
• Measurements of azimuthal anisotropies of jet production in Pb+Pb collisions at $\sqrt{s_{NN}}=$ 5.02 TeV with the ATLAS detector
• Measurements of the suppression and correlations of dijets in Pb+Pb collisions at $\sqrt{s_{{}_{\text{NN}}}}$ = 5.02 TeV

Cited by in corpus (2)

• Transverse momentum balance of dijets in Xe+Xe collisions at the LHC
• Jet radius dependence of dijet momentum balance and suppression in Pb+Pb collisions at 5.02 TeV with the ATLAS detector