Very High-pT Triggered Dihadron Correlations in PbPb Collisions at 2.76 TeV with CMS

Measurements of dihadron correlations triggered by very high-pT particles in 2.76 TeV PbPb collisions are presented. The analysis explores the full 2011 PbPb data set corresponding to an integrated luminosity of 150μb−1 collected by CMS. Long-range correlations driven by single-particle azimuthal anisotropies (characterized by the Fourier harmonics, vn) are measured up to pT∼50 GeV/c. After subtracting the v2 - v4 harmonic components, the associated particle yields on the near and away side of the residual jet-like dihadron correlations are studied over a wide kinematic range in trigger and associated particle pT, as a function of collision centrality. By comparing to pp data at the same energy, a suppression of about 50% in the away-side associated yield is observed for pTassoc>3GeV/c. The yield is found to be significantly enhanced up to a factor of 3-4 on the away side at pTassoc∼0.5GeV/c. A moderate enhancement is suggested on the near side.