Study of charged particle production at high $p_{\mathrm{T}}$ using event topology in pp, p$-$Pb and Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

Abstract

This letter reports measurements which characterize the underlying event associated with hard scatterings at mid-pseudorapidity ($|\eta |<0.8$) in pp, p$-$Pb and Pb$-$Pb collisions at centre-of-mass energy per nucleon pair, $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. The measurements are performed with ALICE at the LHC. Different multiplicity classes are defined based on the event activity measured at forward rapidities. The hard scatterings are identified by the leading particle defined as the charged particle with the largest transverse momentum ($p_{\mathrm{T}}$) in the collision and having $8<p_{\mathrm{T}}<15$ GeV/$c$. The $p_{\mathrm{T}}$ spectra of associated particles ($0.5\le p_{\mathrm{T}}<6$ GeV/$c$) are measured in different azimuthal regions defined with respect to the leading particle direction: toward, transverse, and away. The associated charged particle yields in the transverse region are subtracted from those of the away and toward regions. The remaining jet-like yields are reported as a function of the multiplicity measured in the transverse region. The measurements show a suppression of the jet-like yield in the away region and an enhancement of high-$p_{\mathrm{T}}$ associated particles in the toward region in central Pb$-$Pb collisions, as compared to minimum-bias pp collisions. These observations are consistent with previous measurements that used two-particle correlations, and with an interpretation in terms of parton energy loss in a high-density quark gluon plasma. These yield modifications vanish in peripheral Pb$-$Pb collisions and are not observed in either high-multiplicity pp or p$-$Pb collisions.

arXiv comment22 pages, 5 captioned figures, 1 table, authors from page 17, published version, figures at http://alice-publications.web.cern.ch/node/7843

References in corpus (42)

• An Introduction to PYTHIA 8.2
• Experimental and Theoretical Challenges in the Search for the Quark Gluon Plasma: The STAR Collaboration's Critical Assessment of the Evidence from RHIC Collisions
• Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration
• EPOS LHC : test of collective hadronization with LHC data
• Herwig 7.0 / Herwig++ 3.0 Release Note
• Radiative energy loss of high energy quarks and gluons in a finite volume quark-gluon plasma
• Tuning PYTHIA 8.1: the Monash 2013 Tune
• Performance of the ALICE Experiment at the CERN LHC
• Observation of Long-Range Near-Side Angular Correlations in Proton-Proton Collisions at the LHC
• Heavy Ion Collisions: The Big Picture, and the Big Questions
• Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions
• Evidence for collectivity in pp collisions at the LHC
• Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV
• Jet quenching in high-energy heavy-ion collisions
• Small System Collectivity in Relativistic Hadron and Nuclear Collisions
• Centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Direct observation of dijets in central Au+Au collisions at sqrt(s_NN) = 200 GeV
• Harmonic decomposition of two-particle angular correlations in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Centrality dependence of particle production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$= 5.02 TeV
• Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV
• Anisotropic flow of charged particles in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC
• The Angantyr model for Heavy-Ion Collisions in PYTHIA8
• Multiplicity dependence of light-flavor hadron production in pp collisions at $\sqrt{s}$ = 7 TeV
• Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}$ = 5.02 TeV
• Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Hadron production in p+p, p+Pb, and Pb+Pb collisions with the HIJING 2.0 model at energies available at the CERN Large Hadron Collider
• Multiplicity dependence of (multi-)strange hadron production in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Charged-particle production as a function of multiplicity and transverse spherocity in pp collisions at $\sqrt{s}$ = 5.02 and 13 TeV
• Constraints on jet quenching in p-Pb collisions at $\sqrt{{\mathbf{s}}_{\mathbf{NN}}}$ = 5.02 TeV measured by the event-activity dependence of semi-inclusive hadron-jet distributions
• Absence of jet quenching in peripheral nucleus-nucleus collisions
• Probing Collective Effects in Hadronisation with the Extremes of the Underlying Event
• Combining Difficulty Ranking with Multi-Armed Bandits to Sequence Educational Content
• Analysis of the apparent nuclear modification in peripheral Pb-Pb collisions at 5.02 TeV
• Jet-like correlations with neutral pion triggers in pp and central Pb-Pb collisions at 2.76 TeV
• Probing color reconnection with underlying event observables at the LHC energies
• Multi-Parton Interactions in pp collisions from Machine Learning-based regression
• Transverse nucleon structure and multiparton interactions
• Underlying event measurements in $p$+$p$ collisions at $\sqrt{s}=200$ GeV at RHIC
• Disentangling the hard gluon Bremsstrahlung effects from the relative transverse activity classifier in pp collisions
• Apparent modification of the jet-like yield in proton-proton collisions with large underlying event
• Collisional Energy Loss of a Fast Parton in a QGP

Cited by in corpus (7)

• Probing strangeness with event topology classifiers in pp collisions at energies available at the CERN Large Hadron Collider with the rope hadronization mechanism in PYTHIA
• Particle production as a function of charged-particle flattenicity in pp collisions at $\sqrt{s}$ = 13 TeV
• Thermodynamical string fragmentation and string density effects in jets
• Investigating radial flow-like effects via pseudorapidity and transverse spherocity dependence of particle production in pp collisions at the LHC
• Flattenicity as "centrality" estimator in p-Pb collisions simulated with PYTHIA 8.312 Angantyr
• Investigating jet induced identified hadron productions from the relative transverse activity classifier in pp collision at LHC
• Topological production of charmonia with event-shape engineering in $pp$ collisions at $\sqrt{s}=13$ TeV using PYTHIA8