Fluctuation of the Initial Conditions and Its Consequences on Some Observables

TL;DR

This paper investigates how event-by-event fluctuations in initial conditions affect various observables in high-energy nuclear collisions, revealing non-trivial effects like enhanced high-pT particle production and the ridge phenomenon.

Contribution

It demonstrates the impact of initial condition fluctuations on observables and introduces their role in phenomena like the ridge effect in nuclear collisions.

Findings

Fluctuations increase high-pT particle production.

They decrease v2 in forward/backward regions.

Fluctuations can produce the ridge effect.

Abstract

We show effects of the event-by-event fluctuation of the initial conditions (IC) in hydrodynamic description of high-energy nuclear collisions on some observables. Such IC produce not only fluctuations in observables but, due to their bumpy structure, several non-trivial effects appear. They enhance production of isotropically distributed high-pT particles, making v2 smaller there. Also, they reduce v2 in the forward and backward regions where the global matter density is smaller, so where such effects become more efficacious. They may also produce the so-called ridge effect in the two large-pT particle correlation.