Phenomenology of collinear photon emission from quark-gluon plasma in AA collisions
B. G. Zakharov
L.D. Landau Institute for Theoretical Physics, 117334 Moscow, Russia
We study the role of running coupling and
the effect of variation of the thermal quark mass on
contribution of the collinear bremsstrahlung and annihilation
to photon emission in AA collisions in a scheme
similar to that used in our previous jet quenching analyses.
We find that
for a scenario with the thermal quark mass
MeV contribution of the
higher order collinear processes summed with the 2→ 2 processes
can explain a considerable part ( %)
of the experimental photon spectrum
for Au+Au collisions at TeV.
But for mq=300 MeV and for the
thermal quark mass predicted by the HTL scheme
the theoretical predictions underestimate
considerably the experimental spectrum.