English

Model comparison for initial density fluctuations in high energy heavy ion collisions

High Energy Physics - Phenomenology 2020-12-01 v2 Nuclear Theory

Abstract

Four models for the initial conditions of a fluid dynamic description of high energy heavy ion collisions are analysed and compared. We study expectation values and event-by-event fluctuations in the initial transverse energy density profiles from Pb-Pb collisions. Specifically, introducing a Fourier-Bessel mode expansion for fluctuations, we determine expectation values and two-mode correlation functions of the expansion coefficients. The analytically solveable independent point-sources model is compared to an initial state model based on Glauber theory and two models based on the Color Glass Condensate framework. We find that the large wavelength modes of all investigated models show universal properties for central collisions and also discuss to which extent general properties of initial conditions can be understood analytically.

Keywords

Cite

@article{arxiv.2005.11284,
  title  = {Model comparison for initial density fluctuations in high energy heavy ion collisions},
  author = {Stefan Floerchinger and Eduardo Grossi and Kianusch Vahid Yousefnia},
  journal= {arXiv preprint arXiv:2005.11284},
  year   = {2020}
}

Comments

18 pages, 8 figures, results are attached as ancillary files; presentation in section IV rephrased for clarification, typos corrected, references added

R2 v1 2026-06-23T15:44:44.467Z