# Characterization of the initial state and QGP medium from a combined Bayesian analysis of LHC data at 2.76 and 5.02 TeV

## TL;DR

This paper uses Bayesian analysis to calibrate a heavy-ion collision model with LHC data, providing new constraints on initial-state entropy and QGP transport properties, including temperature-dependent shear viscosity.

## Contribution

It introduces a comprehensive Bayesian calibration of a collision model with LHC data at two energies, yielding novel constraints on initial conditions and QGP transport coefficients.

## Key findings

- Model describes multiplicity, pT, and flow data at both energies.
- Provides quantitative estimates of shear viscosity as a function of temperature.
- Constrains initial-state entropy deposition scaling.

## Abstract

We perform a global Bayesian analysis of a modern event-by-event heavy-ion collision model and LHC data at $\sqrt s$ = 2.76 and 5.02 TeV. After calibration, the model simultaneously describes multiplicity, transverse momentum, and flow data at both beam energies. We report new constraints on the scaling of initial-state entropy deposition and QGP transport coefficients, including a quantitative estimate of the temperature-dependent shear viscosity $(\eta/s)(T)$.