First longitudinal coefficient a_{1} in Xe-Xe and Pb-Pb collisions as a function of <dNch/deta>

Scope: PWG
PWG-CF (Flow and Correlations)
Energy
5.02 TeV
5.44 TeV
System
Pb-Pb
Xe-Xe
Figure Image
Figure image (.eps)
Figure image (.pdf)
Figure Caption

The first longitudinal coefficient a1 as a function of <dNch/deta> in Pb-Pb collisions at √sNN = 5.02 TeV and Xe-Xe collisions at √sNN = 5.44 TeV, compared between data and MC HIJING. Statistical and systematic uncertainties are included.

Detail description

The first longitudinal coefficient a1 as a function of <dNch/deta> in Pb-Pb collisions at √sNN = 5.02 TeV(LHC18r, LHC18q) and Xe-Xe collisions at √sNN = 5.44 TeV (LHC17n), compared between data and MC HIJING. a1 was computed EbyE using Legendre polynomial decomposition. For Pb-Pb data, both periods with different polarities LHC18q and LHC18r were analyzed and merged. The values used for <dNch/deta> are published values from ALICE (arXiv:1512.06104; arXiv:1805.04432). Statistical and systematic uncertainties are included. Systematic errors are averaged along centrality. Systematic errors in Xe-Xe data are assigned from Pb-Pb data systematic errors.

Event acceptance:

  • 0.2<pT<2.0 GeV/c
  • -0.8<eta<0.8
  • -8<Vz<8 cm
  • FilterBit: 768
  • TPC Ncls > 70
  • TPC N crossed rows >70
  • number of eta bins: 16
  • Pb-Pb chi2/NDF<2.5
  • Xe-Xe chi2/NDF<4
  • Pileup cuts applied for Pb-Pb using DPG cuts (https://indico.cern.ch/event/957574/contributions/4094213/att achments/2141330/3608130/DPG_AliceWeek_20201111.pdf)
  • Charged tracks only

Systematic checks:

  • chi2/NDF<2.3 (Pb-Pb)
  • chi2/NDF<2 (Pb-Pb)
  • chi2/NDF<3.5 (Xe-Xe)
  • No cut/looser/even more looser/very loose pileup cut (Pb-Pb)
  • TPC N crossed rows >100
  • TPC Ncls >80
  • -7<Vz<7cm
  • -6<Vz<6cm
  • -8<Vz<-0.2 && 0.2<Vz<8 cm
  • FilterBit: 96
  • number of eta bins: 32