Long-range and short-range dihadron angular correlations in central PbPb collisions at psNN = 2:76 TeV
Journal
Journal of High Energy Physics
Journal Volume
2011
Journal Issue
7
Date Issued
2011
Abstract
First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV over a broad range in relative pseudorapidity () and the full range of relative azimuthal angle (). The data were collected with the CMS detector, at the LHC. A broadening of the away-side ( ) azimuthal correlation is observed at all , as compared to the measurements in pp collisions. Furthermore, long-range dihadron correlations in are observed for particles with similar values. This phenomenon, also known as the "ridge", persists up to at least
= 4. For particles with transverse momenta (p T ) of 2-4 GeV/c, the ridge is found to be most prominent when these particles are correlated with particles of p T = 2-6 GeV/c, and to be much reduced when paired with particles of p T = 10-12 GeV/c.
Type
journal article