Measurement with the ATLAS detector of multi-particle azimuthal correlations in p Pb collisions at √sNN= 5.02 TeV. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics Volume 725, Issue 1-3, 9 August 2013, Pages 60-78

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 μb-1, the parameter v2has been obtained using two- and four-particle cumulants over the pseudorapidity range "η"