Longitudinal Structure of Quark-Gluon Plasma Unveiled Through Nuclear Deformations

TL;DR

This paper introduces a novel method using nuclear deformations in collisions to analyze the longitudinal structure of quark-gluon plasma, revealing that deformation affects flow magnitude but not its profile.

Contribution

It presents the first extraction of the complete longitudinal structure of elliptic flow using a dynamical transport model, highlighting the impact of nuclear deformation.

Findings

Deformation enhances the magnitude of elliptic flow $v_2$.

Deformation does not change the longitudinal profile of $v_2$.

The method separates rapidity dependence from decorrelations.

Abstract

The study of quark-gluon plasma (QGP) is hindered by our limited understanding of its initial conditions, particularly its longitudinal structure. We propose a novel approach that entails analyzing collisions involving nuclei of similar masses but different deformations. This strategy allows us to vary the initial conditions and collective expansion of the QGP, while minimizing the influence of non-flow correlations. Using a dynamical transport model, we have for the first time extracted the complete longitudinal structure of elliptic flow ($v_2$). Our findings reveal that although deformation significantly enhances the overall magnitude of $v_2$, it does not alter its longitudinal profile. This approach not only enables the separation of the rapidity dependence of flow from its rapidity decorrelations but also prompts further investigation into other nuclear structural features, such as nuclear skin thickness, to advance our understanding of the QGP's initial conditions.