Modeling Quark Gluon Plasma Using CHIMERA

TL;DR

This paper introduces CHIMERA, a comprehensive modeling framework for Quark Gluon Plasma evolution that combines initial state modeling, viscous hydrodynamics, and hadronic cascade, to better fit experimental data and extract key QGP parameters.

Contribution

The paper presents CHIMERA, an integrated framework that models QGP evolution from initial collision to final state, enabling simultaneous comparison with multiple experimental observables.

Findings

Optimal initial temperature and viscosity parameters identified.

Model accurately reproduces HBT radii, spectra, and flow data.

Framework constrains QGP properties difficult to measure directly.

Abstract

We attempt to model Quark Gluon Plasma (QGP) evolution from the initial Heavy Ion collision to the final hadronic gas state by combining the Glauber model initial state conditions with eccentricity fluctuations, pre-equilibrium flow, UVH2+1 viscous hydrodynamics with lattice QCD Equation of State (EoS), a modified Cooper-Frye freeze-out and the UrQMD hadronic cascade. We then evaluate the model parameters using a comprehensive analytical framework which together with the described model we call CHIMERA. Within our framework, the initial state parameters, such as the initial temperature (T$_{\mathrm{init}}$), presence or absence of initial flow, viscosity over entropy density ($\eta$/s) and different Equations of State (EoS), are varied and then compared simultaneously to several experimental data observables: HBT radii, particle spectra and particle flow. $\chi^2$/nds values from comparison to the experimental data for each set of initial parameters will then used to find the optimal description of the QGP with parameters that are difficult to obtain experimentally, but are crucial to understanding of the matter produced.