Eccentricity distributions in nucleus-nucleus collisions

Li Yan (1) , Jean-Yves Ollitrault (1) , Arthur M. Poskanzer (2)

1 IPHT - Institut de Physique Théorique - UMR CNRS 3681
2 LBNL - Lawrence Berkeley National Laboratory [Berkeley]

We propose a new parametrization of the distribution of the initial eccentricity in a nucleus-nucleus collision at a fixed centrality, which we name the Elliptic Power distribution. It is a two-parameter distribution, where one of the parameters corresponds to the intrinsic eccentricity, while the other parameter controls the magnitude of eccentricity fluctuations. Unlike the previously used Bessel- Gaussian distribution, which becomes worse for more peripheral collisions, the new Elliptic Power distribution fits several Monte Carlo models of the initial state for all centralities.

Domaines: Physique Nucléaire Théorique [nucl-th]; Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique Nucléaire Expérimentale [nucl-ex]

Li Yan, Jean-Yves Ollitrault, Arthur M. Poskanzer. Eccentricity distributions in nucleus-nucleus collisions. Physics Letters, 2014, 90 (02), ⟨10.1103/PhysRevC.90.024903⟩. ⟨cea-01323620⟩