Energy density and path-length dependence of the fractional momentum loss in heavy-ion collisions at $\sqrt{s_{\rm NN}}$ from 62.4 to 5020 GeV

TL;DR

This study investigates how fractional momentum loss in heavy-ion collisions depends on energy density and path length, revealing linear relationships and potential universality across different energies and particle types.

Contribution

It introduces a comprehensive analysis of fractional momentum loss dependence on energy density and path length across various collision energies, highlighting universal behavior and linear relationships.

Findings

Fractional momentum loss increases linearly with ({5}_{Bj} au_{0})^{3/8}L.

A universal functional form of S_loss vs. ({5}_{Bj} au_{0})^{3/8}L is observed.

Linear relationship between S_loss and L for identified charged hadrons.

Abstract

In this work a study of the fractional momentum loss ($S_{\rm loss}$) as a function of the characteristic path-length ($L$) and the Bjorken energy density times the equilibration time ($\epsilon_{\rm Bj}\tau_{0}$) for heavy-ion collisions at different $\sqrt{s_{\rm NN}}$ is presented. The study has been conducted using inclusive charged particles from intermediate to large transverse momentum ($5<p_{\rm T}<20$ GeV/$c$). Within uncertainties and for all the transverse momentum values which were explored, the fractional momentum loss linearly increases with $({\epsilon_{\rm Bj}\tau_{0}})^{3/8}$$L$. The functional form of $S_{\rm loss}$ vs. $({\epsilon_{\rm Bj}\tau_{0}})^{3/8}$$L$ seems to be universal. Moreover, for identified charged hadrons a linear relationship between $S_{\rm loss}$ and $L$ is also observed. The behaviour of data could provide important information aimed to understand the parton energy loss mechanism in heavy-ion collisions and some insight into the expected effect for small systems.