Factorization of two-particle distributions in AMPT simulations of Pb-Pb collisions at $\sqrt{{\mathbf{s}}_{\text{NN}}}$ = 5.02 TeV

Abstract

The flow ansatz states that the single-particle distribution of a given event can be described in terms of the complex flow coefficients $V_n$. Multi-particle distributions can therefore be expressed as products of these single-particle coefficients; a property commonly referred to as factorization. The amplitudes and phases of the coefficients fluctuate from event to event, possibly breaking the factorization assumption for event-sample averaged multi-particle distributions. Furthermore, non-flow effects such as di-jets may also break the factorization assumption. The factorization breaking with respect to pseudorapidity $\eta$ provides insights into the fluctuations of the initial conditions of heavy ion collisions and can simultaneously be used to identify regions of the phase space which exhibit non-flow effects. These proceedings present a method to perform a factorization of the two-particle Fourier coefficients $V_{n\Delta }({\eta }_a,{\eta }_b)$ which is largely independent of detector effects. AMPT model calculations of Pb-Pb collisions at $\sqrt{s_{\text{NN}}}=5.02$ TeV are used to identify the smallest $|\Delta \eta |$-gap necessary for the factorization assumption to hold. Furthermore, a possible $\Delta \eta$-dependent decorrelation effect in the simulated data is quantified using the empirical parameter $F_2^{\eta }$. The decorrelation effect observed in the AMPT calculations is compared to results by the CMS collaboration for Pb-Pb collisions at $\sqrt{s_{\text{NN}}}=2.76$ TeV.

8 pages, 7 figures, conference proceedings, submitted to Journal of Physics: Conference Series (JPCS)

References in corpus (1)

• Forward-backward correlations between multiplicities in windows separated in azimuth and rapidity