Azimuthal anisotropy of jet particles in p-Pb and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

Abstract

The azimuthal anisotropy of particles associated with jets (jet particles) at midrapidity is measured for the first time in p-Pb and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV down to transverse momentum ($p_{\mathrm{T}}$) of 0.5 GeV/$c$ and 2 GeV/$c$, respectively, with ALICE. The results obtained in p-Pb collisions are based on a novel three-particle correlation technique. The azimuthal anisotropy coefficient $v_2$ in high-multiplicity p-Pb collisions is positive, with a significance reaching 6.8$\sigma$ at low $p_{\mathrm{T}}$, and its magnitude is smaller than in semicentral Pb-Pb collisions. In contrast to the measurements in Pb-Pb collisions, the $v_2$ coefficient is also found independent of $p_{\mathrm{T}}$ within uncertainties. Comparisons with the inclusive charged-particle $v_2$ and with AMPT calculations are discussed. The predictions suggest that parton interactions play an important role in generating a non-zero jet-particle $v_2$ in p-Pb collisions, even though they overestimate the reported measurement. These observations shed new insights on the understanding of the origin of the collective behaviour of jet particles in small systems such as p-Pb collisions, and provide significant stringent new constraints to models.

arXiv comment24 pages, 8 captioned figures, 2 tables, authors from page 19, published version, figures at http://alice-publications.web.cern.ch/node/8865

References in corpus (29)

• A Multi-Phase Transport Model for Relativistic Heavy Ion Collisions
• Methods for analyzing anisotropic flow in relativistic nuclear collisions
• Flow Study in Relativistic Nuclear Collisions by Fourier Expansion of Azimuthal Particle Distributions
• Performance of the ALICE Experiment at the CERN LHC
• EPS09 - a New Generation of NLO and LO Nuclear Parton Distribution Functions
• HIJING 1.0: A Monte Carlo Program for Parton and Particle Production in High Energy Hadronic and Nuclear Collisions
• The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events
• Formation of superdense hadronic matter in high energy heavy-ion collisions
• ZPC 1.0.1: a parton cascade for ultrarelativistic heavy ion collisions
• Performance of the ALICE VZERO system
• Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
• High $p_T$ Azimuthal Asymmetry in Non-central A+A at RHIC
• Comparison of the Color Glass Condensate to di-hadron correlations in proton-proton and proton-nucleus collisions
• Heavy Ion Collisions: Achievements and Challenges
• Novel Collective Phenomena in High-Energy Proton-Proton and Proton-Nucleus Collisions
• Evidence for BFKL and saturation dynamics from di-hadron spectra at the LHC
• Anisotropic parton escape is the dominant source of azimuthal anisotropy in transport models
• Cronin Effect in Hadron Production off Nuclei
• Anisotropic parton escape is the dominant source of azimuthal anisotropy in transport models
• The Azimuthal Asymmetry at large p_t seem to be too large for a ``Jet Quenching''
• Eliminating experimental bias in anisotropic-flow measurements of high-energy nuclear collisions
• Further developments of a multi-phase transport model for relativistic nuclear collisions
• Effects of non-uniform acceptance in anisotropic flow measurement
• Multiple scattering effects on heavy meson production in p+A collisions at backward rapidity
• Centrality dependence of charged jet production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• The Collectivity of Heavy Mesons in Proton-Nucleus Collisions
• Investigating the elliptic anisotropy of identified particles in p--Pb collisions with a multi-phase transport model
• Charm quarks are more hydrodynamic than light quarks in final-state elliptic flow
• Testing the collectivity in large and small colliding systems with test particles

Cited by in corpus (1)

• Evidence for similar collectivity of high transverse momentum particles in pPb and PbPb collisions