# In-Medium Bottomonium Production in Heavy-Ion Collisions

## TL;DR

This paper models bottomonium production in heavy-ion collisions using advanced transport equations, incorporating in-medium effects, off-equilibrium dynamics, and updated medium properties, and compares results with experimental data.

## Contribution

It introduces an improved transport model with in-medium binding energies and off-equilibrium effects, providing a more accurate description of bottomonium yields and spectra in heavy-ion collisions.

## Key findings

- Off-equilibrium bottom-quark spectra significantly influence bottomonium $p_T$ spectra.
- In-medium binding energies from a thermodynamic $T$-matrix improve dissociation rate calculations.
- The model successfully describes RHIC and LHC bottomonium data.

## Abstract

We study bottomonium production in heavy-ion collisions using a transport model which utilizes kinetic-rate and Boltzmann equations to calculate the energy, centrality and transverse-momentum ($p_T$) dependence of the yields. Both gluo-dissociation and inelastic parton-induced break-up including interference effects are improved over previous work by using in-medium binding energies from a thermodynamic $T$-matrix approach. A coalescence model with bottom-quark spectra from Langevin simulations is implemented to account for thermal off-equilibrium effects in the $p_T$-spectra of the regeneration contribution. We also update the equation of state for the bulk medium by extracting it from lattice-QCD results. A systematic analysis of bottomonium observables is conducted in comparison to RHIC and LHC data. In particular, the off-equilibrium bottom-quark spectra are found to play an important role in the bottomonium $p_T$ spectra.