Fast Dynamical Evolution of Hadron Resonance Gas via Hagedorn States

TL;DR

This paper demonstrates how Hagedorn states facilitate rapid thermalization of hadron gases in high-energy collisions, using microscopic transport simulations that respect detailed balance to match experimental data.

Contribution

It introduces a microscopic simulation approach showing Hagedorn states drive quick thermalization in hadron gases, a novel insight into hadronization dynamics.

Findings

Hagedorn states enable thermalization within 1-2 fm/c.

Simulation results match ALICE experimental data.

Hagedorn states are crucial for understanding hadronization.

Abstract

Hagedorn states are the key to understand how all hadrons observed in high energy heavy ion collisions seem to reach thermal equilibrium so quickly. An assembly of Hagedorn states is formed in elementary hadronic or heavy ion collisions at hadronization. Microscopic simulations within the transport model UrQMD allow to study the time evolution of such a pure non-equilibrated Hagedorn state gas towards a thermally equilibrated Hadron Resonance Gas by using dynamics, which unlike strings, fully respect detailed balance. Propagation, repopulation, rescatterings and decays of Hagedorn states provide the yields of all hadrons up to a mass of m=2.5 GeV. Ratios of feed down corrected hadron multiplicities are compared to corresponding experimental data from the ALICE collaboration at LHC. The quick thermalization within t=1-2 fm\c of the emerging Hadron Resonance Gas exposes Hagedorn states as a tool to understand hadronization.