CMS-PAS-HIN-17-006

CMS-PAS-HIN-17-006
Pseudorapidity distributions of charged hadrons in XeXe collisions at $\sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.44 TeV
CMS Collaboration
May 2018

Abstract: Measurements of the pseudorapidity distributions of charged hadrons produced in xenon-xenon collisions at $\sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.44 TeV are presented. The measurements are based on data collected by the CMS experiment at the CERN LHC. The yield of primary charged hadrons produced in non-single-diffractive xenon-xenon collisions in the pseudorapidity range $\|\eta \| < $ 3.2 is determined using the silicon pixel detector in the CMS tracking system. For events with the largest overlap between the colliding nuclei, the charged-hadron pseudorapidity density at midrapidity is found to be 1187 $\pm$ 36 (syst.). The rapidity distribution of charged hadrons is also presented and is found to be independent of rapidity around midrapidity, a feature that is not predicted by Monte Carlo event generators. Comparisons of per-participant charged-particle multiplicities between xenon-xenon and lead-lead collisions at similar energies show that particle production is driven by the collision geometry instead of the system size.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, PLB 799 (2019) 135049. The superseded preliminary plots can be found here.

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