Speaker
Wei Li
(MIT)
Description
Azimuthal anisotropy harmonics have been measured in ultra-central PbPb
collisions at a center-of-mass energy per nucleon pair of 2.76 TeV. Top central 0.2\% PbPb collisions
have been collected using a unique trigger on total energy at forward
hadronic calorimeter and total multiplicity of hits on pixel tracker by
the CMS experiment during 2011 LHC PbPb run. A total of about 1.8 million
events were recorded with top 0.2\% collision centrality. Fourier flow
harmonics ($v_n$) are extracted from Fourier decomposition of long-range dihadron correlations
as a function of particle transverse momentum. The relative ratio of different $v_n$ provides a direct constraint on the
eta/s of the QGP matter, independent of the initial condition models.
Author
Collaboration CMS
(CERN)
