Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at nucleon-nucleon center-of-mass energy = 2.76 TeV
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S. Chatrchyan
- Function : Author
S. Baffioni
- Function : Author
- PersonId : 20331
- IdHAL : stephanie-barrillon
- ORCID : 0000-0002-7075-1673
P. Busson
- Function : Author
- PersonId : 741166
- IdHAL : phbusson
- ORCID : 0000-0001-6027-4511
- IdRef : 033562466
R. Granier de Cassagnac
- Function : Author
- PersonId : 739189
- IdHAL : raphgrandecass
- ORCID : 0000-0002-1275-7292
- IdRef : 132136651
C. Mironov
- Function : Author
- PersonId : 1196248
- IdHAL : camelia-mironov
P. Paganini
- Function : Author
- PersonId : 739173
- IdHAL : pascal-paganini
- ORCID : 0000-0001-9580-683X
- IdRef : 183219406
C. Collard
- Function : Author
- PersonId : 753602
- IdHAL : caroline-collard
- ORCID : 0000-0002-5230-8387
- IdRef : 223465992
P. van Hove
- Function : Author
- PersonId : 742701
- IdHAL : pierre-van-hove
- ORCID : 0000-0002-2431-3381
- IdRef : 264250834
M. Gouzevitch
- Function : Author
- PersonId : 741096
- IdHAL : maxime-gouzevitch
- ORCID : 0000-0002-5524-880X
- IdRef : 13627160X
M. Lethuillier
- Function : Author
- PersonId : 740178
- IdHAL : morgan-lethuillier
- ORCID : 0000-0001-6185-2045
- IdRef : 090177835
V. Sordini
- Function : Author
- PersonId : 739810
- IdHAL : viola-sordini
- ORCID : 0000-0003-0885-824X
- IdRef : 128184035
S. Viret
- Function : Author
- PersonId : 1093632
- IdHAL : seb-viret
- ORCID : 0000-0002-1935-623X
Abstract
The anisotropy of the azimuthal distributions of charged particles produced in PbPb collisions with a nucleon-nucleon center-of-mass energy of 2.76 TeV is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter defined as the second coefficient in a Fourier expansion of the particle invariant yields, is extracted using the event-plane method, two- and four-particle cumulants, and Lee--Yang zeros. The anisotropy is presented as a function of transverse momentum (pt), pseudorapidity (eta) over a broad kinematic range: 0.3 < pt < 20 GeV, abs(eta) < 2.4, and in 12 classes of collision centrality from 0 to 80%. The results are compared to those obtained at lower center-of-mass energies, and various scaling behaviors are examined. When scaled by the geometric eccentricity of the collision zone, the elliptic anisotropy is found to obey a universal scaling with the transverse particle density for different collision systems and center-of-mass energies.