Measurement of substructure-dependent jet suppression in Pb+Pb collisions at 5.02 TeV with the ATLAS detector

Abstract

The ATLAS detector at the Large Hadron Collider has been used to measure jet substructure modification and suppression in Pb+Pb collisions at a nucleon-nucleon center-of-mass energy $\sqrt{s_{{}_{\mathrm{NN}}}}=5.02\mathrm{TeV}$ in comparison with $pp$ collisions at $\sqrt{s}=5.02\mathrm{TeV}$. The Pb+Pb data, collected in 2018, have an integrated luminosity of $1.72\mathrm{n}{\mathrm{b}}^{-1}$, while the $pp$ data, collected in 2017, have an integrated luminosity of $260{\mathrm{pb}}^{-1}$. Jets used in this analysis are clustered using the anti-$k_t$ algorithm with a radius parameter $R=0.4$. The jet constituents, defined by both tracking and calorimeter information, are used to determine the angular scale $r_{\mathrm{g}}$ of the first hard splitting inside the jet by reclustering them using the Cambridge-Aachen algorithm and employing the soft-drop grooming technique. The nuclear modification factor, $R_{\mathrm{AA}}$, used to characterize jet suppression in Pb+Pb collisions, is presented differentially in $r_{\mathrm{g}}$, jet transverse momentum, and in intervals of collision centrality. The $R_{\mathrm{AA}}$ value is observed to depend significantly on jet $r_{\mathrm{g}}$. Jets produced with the largest measured $r_{\mathrm{g}}$ are found to be twice as suppressed as those with the smallest $r_{\mathrm{g}}$ in central Pb+Pb collisions. The $R_{\mathrm{AA}}$ values do not exhibit a strong variation with jet $p_{\mathrm{T}}$ in any of the $r_{\mathrm{g}}$ intervals. The $r_{\mathrm{g}}$ and $p_{\mathrm{T}}$ dependence of jet $R_{\mathrm{AA}}$ is qualitatively consistent with a picture of jet quenching arising from coherence and provides the most direct evidence in support of this approach.

50 pages in total, author list starting page 33, 14 figures, 1 table, published in Phys. Rev. C. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2021-09/

References in corpus (13)

• An Introduction to PYTHIA 8.2
• Glauber Modeling in High Energy Nuclear Collisions
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Study of the material of the ATLAS inner detector for Run 2 of the LHC
• Measurements of the Nuclear Modification Factor for Jets in Pb+Pb Collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the ATLAS Detector
• Measurement of jet fragmentation in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV
• Sensitivity of jet substructure to jet-induced medium response
• First measurement of large area jet transverse momentum spectra in heavy-ion collisions
• Measurements of jet vetoes and azimuthal decorrelations in dijet events produced in $pp$ collisions at $\sqrt{s}$ = 7 TeV using the ATLAS detector
• Inclusive jet and hadron suppression in a multistage approach
• Measurements of azimuthal anisotropies of jet production in Pb+Pb collisions at $\sqrt{s_{NN}}=$ 5.02 TeV with the ATLAS detector
• An overview of experimental results from ultra-relativistic heavy-ion collisions at the CERN LHC: hard probes
• Differential measurements of jet substructure and partonic energy loss in Au$+$Au collisions at $\sqrt{s_{\mathrm{NN}}}=200$ GeV

Cited by in corpus (14)

• Measurement of suppression of large-radius jets and its dependence on substructure in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ATLAS detector
• Hard jet substructure in a multistage approach
• Isolating perturbative QCD splittings in heavy-ion collisions
• Measurement of groomed event shape observables in deep-inelastic electron-proton scattering at HERA
• Selection bias effects on high-$p_{\mathrm{T}}$ yield and correlation measurements in Oxygen+Oxygen collisions
• Search for quasi-particle scattering in the quark-gluon plasma with jet splittings in pp and Pb$-$Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}=5.02$ TeV
• Probing the mass effect of heavy quark jets in high-energy nuclear collisions
• Phenomenological study of the angle between jet axes in heavy-ion collisions
• Jet substructure measurements in heavy-ion collisions
• Quantifying the Jet Energy Loss in Pb+Pb collisions at LHC
• D${}^0$-meson-tagged jet axes difference in proton-proton collisions at $\sqrt{\text{s}}=5.02$ TeV
• Deriving a parton shower for jet thermalization in QCD plasmas
• A modular perspective to the jet suppression from a small to large radius in very high transverse momentum jets
• The effect of recoils on soft-drop-groomed observables in $\gamma$-tagged jets in a multistage approach