Abstract:

In order to study further the long-range correlations (“ridge”) observed recently in p+Pb collisions at sNN−−−√ = 5:02 TeV, the second-order azimuthal anisotropy parameter of charged particles, v2, has been measured with the cumulant method using the ATLAS detector at the LHC. In a data sample corresponding to an integrated luminosity of approximately 1 microbarn-1, the parameter v2 has been obtained using two- and four-particle cumulants over the pseudorapidity range |η| tent of the p+Pb collision system, the large magnitude of v2 and its similarity to hydrodynamic predictions provide additional evidence for the importance of final-state effects in p+Pb reactions. In order to study further the long-range correlations (''ridge'') observed recently in p+Pb collisions at s_N_N=5.02 TeV, the second-order azimuthal anisotropy parameter of charged particles, v_2, has been measured with the cumulant method using the ATLAS detector at the LHC. In a data sample corresponding to an integrated luminosity of approximately 1 @mb^-^1, the parameter v_2 has been obtained using two- and four-particle cumulants over the pseudorapidity range |@h|b reactions.