Eccentricity and elliptic flow in pp collisions at the LHC

Abstract

High-multiplicity proton-proton collisions at the LHC may exhibit collective phenomena such as elliptic flow. We study this issue using DIPSY, a brand-new Monte Carlo event generator which features almost-NLO BFKL dynamics and describes the transverse shape of the proton including all fluctuations. We predict the eccentricity of the collision as a function of the multiplicity and estimate the magnitude of elliptic flow. We suggest that flow can be signaled by a sign change in the four-particle azimuthal correlation.

4 pages, talk given at Quark Matter 2011. v2: added a new plot of the four-particle nonflow correlation in DIPSY vs. a rough parametrization of the preliminary ALICE data