BARC/PUB/2012/0938

 
 

Azimuthal Anisotropy of Charged Particles at High Transverse Momenta in Pb-Pb Collisions at √SNN=2.76 TeV

 
     
 
Author(s)

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Abdulsalam, A.; Choudhury, R. K.; Dutta, D.; Kailas, S.; Kumar, V.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; and others
(NPD)

Source

Physical Review Letters, 2012. Vol. 109 (2): pp. 022301

ABSTRACT

The azimuthal anisotropy of charged particles in Pb-Pb collisions at √sNN = 2:76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pT) range up to approximately 60 GeV/c. The data cover both the low-pT region associated with hydrodynamic flow phenomena and the high-pT region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0–60% most-central events, the observed v2 values are found to first increase with pT, reaching a maximum around pT = 3 GeV/c, and then to gradually decrease to almost zero, with the decline persisting up to at least pT = 40 GeV/c over the full centrality range measured.

 
 
SIRD Digital E-Sangrahay