# Energy loss of heavy quarks and $B$ and $D$ meson spectra in PbPb collisions at LHC energies

## TL;DR

This paper investigates the energy loss mechanisms of heavy quarks in quark-gluon plasma and compares theoretical models with experimental data on $D^{0}$ and $B^{+}$ meson suppression at LHC energies.

## Contribution

It introduces a combined approach using reaction operator formalism and generalized dead cone models to accurately describe heavy meson suppression in heavy ion collisions.

## Key findings

- Radiative energy loss alone explains $D^{0}$ meson suppression.
- Combined radiative and collisional models fit $B^{+}$ meson data.
- Both radiative and elastic processes are significant for bottom quarks.

## Abstract

We study the production and evolution of charm and bottom quarks in hot partonic medium produced in heavy ion collisions. The heavy quarks loose energy in the medium which is reflected in the transverse momentum spectra of heavy mesons. The collisional energy loss of heavy quarks has been calculated using QCD calculations. The radiative energy loss is obtained using two models namely reaction operator formalism and generalized dead cone approach. The nuclear modification factors, $R_{AA}$ as a function of transverse momentum by including shadowing and energy loss are calculated for $D^{0}$ and $B^{+}$ mesons in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV and for $D^{0}$ mesons at $\sqrt{s_{NN}}$ = 2.76 TeV and are compared with the recent measurements. The radiative energy loss from generalized dead cone approach alone is sufficient to produce measured $D^{0}$ meson $R_{AA}$ at both the LHC energies. The radiative energy loss from reaction operator formalism plus collisional energy loss gives good description of $D^{0}$ meson $R_{AA}$. For the case of $B^{+}$ meson, the radiative energy loss from generalized dead cone approach plus collisional energy loss gives good description of the CMS data. The radiative process is dominant for charm quarks while for the bottom, both the radiative process and the elastic collisions are important.