Abstract
The event-by-event multiplicity distribution, the energy densities and energy density weighted eccentricity moments (up to ) at early times in heavy-ion collisions at both the BNL Relativistic Heavy Ion Collider (RHIC) () and the CERN Large Hardron Collider (LHC) () are computed in the IP-Glasma model. This framework combines the impact parameter dependent saturation model (IP-Sat) for nucleon parton distributions (constrained by HERA deeply inelastic scattering data) with an event-by-event classical Yang-Mills description of early-time gluon fields in heavy-ion collisions. The model produces multiplicity distributions that are convolutions of negative binomial distributions without further assumptions or parameters. In the limit of large dense systems, the -particle gluon distribution predicted by the Glasma-flux tube model is demonstrated to be nonperturbatively robust. In the general case, the effect of additional geometrical fluctuations is quantified. The eccentricity moments are compared to the MC-KLN model; a noteworthy feature is that fluctuation dominated odd moments are consistently larger than in the MC-KLN model.
5 More- Received 15 July 2012
DOI:https://doi.org/10.1103/PhysRevC.86.034908
©2012 American Physical Society