Dihadron correlations in PbPb collisions at 2.76 TeV with CMS

TL;DR

This paper reports on dihadron correlation measurements in PbPb collisions at 2.76 TeV, revealing a persistent ridge phenomenon and analyzing its dependence on collision parameters and flow coefficients.

Contribution

It provides detailed measurements of the ridge in heavy-ion collisions and explores its relation to flow phenomena, offering new insights into the quark-gluon plasma dynamics.

Findings

Ridge observed up to |DeltaEta|=4

Dependence of ridge on centrality and transverse momentum

Fourier analysis links ridge to flow coefficients

Abstract

Measurements of charged dihadron DeltaEta-DeltaPhi correlations from the CMS collaboration are presented for PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair over a broad range of pseudorapidity and the full range of azimuthal angle. A significant correlated yield is observed for pairs of particles with small DeltaPhi but large longitudinal separation DeltaEta, commonly known as the "ridge". The ridge persists up to at least |DeltaEta| = 4 and the dependence of the ridge region shape and yield on collision centrality and transverse momentum has been measured. A Fourier analysis of the long-range two-particle correlation is presented and discussed in the context of higher order flow coefficients.