# Initial Stages 2021

Jan 10 – 15, 2021
Weizmann Institute of Science
Asia/Jerusalem timezone
See you at IS2023 in Copenhagen in June 2023

## Thermalization time constrained by high-pt QGP tomography

Jan 12, 2021, 7:40 PM
1h 30m
Patio (vDLCC)

### Patio

#### vDLCC

bullet talk (poster) The initial stages of heavy-ion collisions

### Speaker

Mr Stefan Stojku (Institute of Physics Belgrade)

### Description

We show that high-$p_\perp$ $R_{AA}$ and $v_2$ are way more sensitive to the QGP thermalization time, $\tau_0$, than the distributions of low-$p_\perp$ particles, and that the high-$p_\perp$ observables prefer relatively late thermalization at $\tau_0$ ∼ 1 fm/c. To calculate high-$p_\perp$ $R_{AA}$ and $v_2$, we employ our newly developed DREENA-A formalism, which combines state-of-the-art dynamical energy loss model with 3+1dimensional hydrodynamical simulations. The model applies to both light and heavy flavor, and we predict a larger sensitivity of heavy observables to the thermalization time. Elliptic flow parameter $v_2$ is also more sensitive to $\tau_0$ than $R_{AA}$ due to non-trivial differences in the evolution of in-plane and out-of-plane temperature profiles. This presents the first time when a parameter describing bulk QGP has been constrained by high-$p_\perp$ observables and related theory, i.e., by so-called QGP tomography.

### Primary authors

Mr Stefan Stojku (Institute of Physics Belgrade) Dr Jussi Auvinen (Institute of Physics Belgrade) Prof. Marko Djordjevic (University of Belgrade, Faculty of Biology) Dr Pasi Huovinen (Institute of Physics Belgrade) Magdalena Djordjevic (Institute of Physics Belgrade)