Nuclear suppression of light hadrons and single electrons at RHIC and LHC

TL;DR

This paper investigates whether a perturbative QCD model with both radiative and collisional energy loss mechanisms can simultaneously explain nuclear suppression data for light hadrons and single electrons at RHIC and LHC, finding good agreement.

Contribution

It demonstrates that a fixed coupling constant in pQCD can describe multiple suppression observables across different experiments, highlighting the marginal role of collisional energy loss.

Findings

Coupling constant fixed from light hadron data agrees with electron suppression data.

Collisional energy loss is marginal except for bottom quarks at low momenta.

The model provides a unified description of nuclear suppression at RHIC and LHC.

Abstract

We examine whether it is possible to simultaneously describe the experimental data from RHIC and LHC on nuclear suppression of light hadrons and non-photonic single electrons in the pQCD picture of parton energy loss. We perform calculations accounting for both radiative and collisional energy loss. We show that once the coupling constant is fixed from comparison with data on the nuclear modification factor for light hadrons it gives a satisfactory agreement with data on the electron R_{AA} and azimuthal anisotropy v_2. Our results show that the collisional mechanism is only of marginal significance in nuclear suppression of single electrons except for the bottom contribution at momenta < 6-8 GeV.