Hidden asymmetry and long range rapidity correlations

TL;DR

This paper proposes an interpretation of long-range rapidity correlations revealing asymmetries in the system created in high-energy collisions, which challenge the assumption of boost invariance and could impact hydrodynamic modeling.

Contribution

It introduces a new interpretation linking rapidity correlations to asymmetries in the system's density distribution, highlighting event-by-event violations of boost invariance.

Findings

Substantial asymmetric component in rapidity density in central Au-Au collisions

Boost invariance is violated on an event-by-event basis at central rapidity

Potential impact on hydrodynamic expansion models

Abstract

Interpretation of long-range rapidity correlations in terms of the fluctuating rapidity density distribution of the system created in high-energy collisions is proposed. When applied to recent data of the STAR coll., it shows a substantial asymmetric component in the shape of this system in central Au-Au collisions, implying that boost invariance is violated on the event-by-event basis even at central rapidity. This effect may seriously influence the hydrodynamic expansion of the system.