Radiative energy loss in a hot QCD medium: from RHIC to LHC
by
Marta Verweij(Utrecht University - Department of subatomic physics)
→
Europe/Rome
Aula Seminari Edif. Alte Energie (Laboratori Nazionali di Frascati)
Aula Seminari Edif. Alte Energie
Laboratori Nazionali di Frascati
Description
Radiative energy loss by gluon radiation off hard partons in a QCD medium is believed to be the source of the experimentally observed suppression of high p_T hadrons in heavy ion collisions. Existing models of QCD radiative energy loss in a color-charged medium give inconsistent estimates of the coupling strength of the parton to the medium. We will present a side-by-side comparison of two different formalisms to calculate the energy loss of light quarks and gluons: the multiple soft scattering approximation (ASW-MS) and the opacity expansion formalism (ASW-SH and WHDG-rad). Due to different biases, both measurements probe a different part of the medium. The relation between R_AA and I_AA provides information about which kind of energy loss is dominant: fractional energy loss or absorption of the parton in the medium. We also discuss how recent measurements a the LHC could distinguish between different theoretical scenarios.
