Speaker
Dr
Marcus Bluhm
(Laboratoire SUBATECH)
Description
The strong quenching of jets and the suppression of hadron spectra
at high transverse momenta are striking experimental observations
made in high energy nuclear collisions. Both have been interpreted
as signature for the formation of a deconfined plasma of QCD
matter, in which partons suffer a medium-induced energy loss. In
theoretical studies devoted to a parton's radiative energy loss,
however, the damping of radiation within the plasma has so far
widely been neglected.
We investigate the radiative energy loss per unit distance of a
relativistic colour charge traversing as probe an infinite
absorptive plasma. The Landau-Pomeranchuk-Migdal effect is
incorporated as well as modifications due to the polarization of
and damping mechanisms in the medium. The latter are
phenomenologically described by a complex index of refraction,
while the colour charge dynamics is considered in the Abelian
approximation. We find a substantial reduction of the medium-
induced mechanical work in addition to the well known Ter-
Mikaelian effect from the polarization of matter. Moreover, the
formation time of radiated quanta is also drastically reduced,
both for small frequencies, where damping has a minor additional
impact besides the polarization effect, and for larger frequencies.
These effects are more pronounced for larger medium damping
and/or larger initial energy of the charge.
Therefore, we expect that our study will have a significant impact
on the understanding of jet quenching phenomena in ultra-
relativistic heavy-ion collisions at RHIC and even more at LHC.
Author
Dr
Marcus Bluhm
(Laboratoire SUBATECH)
Co-authors
Prof.
Joerg Aichelin
(Laboratoire SUBATECH)
Prof.
Pol Bernard Gossiaux
(Laboratoire SUBATECH)
