Ultracentral heavy ion collisions, transverse momentum and the equation of state

TL;DR

This paper investigates how ultracentral heavy ion collisions probe the quark-gluon plasma, focusing on the effects of the QCD equation of state, initial energy deposition, and centrality selection on transverse momentum.

Contribution

It provides a comprehensive analysis of the factors influencing transverse momentum in ultracentral collisions, emphasizing the role of the QCD equation of state and initial conditions.

Findings

Transverse momentum increases with collision centrality.

Initial energy deposition significantly affects transverse momentum.

The QCD equation of state influences the evolution of the quark-gluon plasma.

Abstract

Ultracentral heavy ion collisions due to their exceptionally large multiplicity probe an interesting regime of quark-gluon plasma where the size is (mostly) fixed and fluctuations in the initial condition dominate. Spurred by the recent measurement of the CMS collaboration we investigate the driving factors of the increase of transverse momentum, including a complete analysis of the influence of the QCD equation of state. Particularly interesting is the influence of the centrality selection as well as the initial energy deposition.