67 research outputs found
Bose enhancement, the Liouville effective action and the high multiplicity tail in p-A collisions
In the framework of dense-dilute CGC approach we study fluctuations in the
multiplicity of produced particles in p-A collisions. We show that the leading
effect that drives the fluctuations is the Bose enhancement of gluons in the
proton wave function. We explicitly calculate the moment generating function
that resums the effects of Bose enhancement. We show that it can be understood
in terms of the Liouville effective action for the composite field which is
identified with the fluctuating density, or saturation momentum of the proton.
The resulting probability distribution turns out to be very close to the
gamma-distribution. We also calculate the first correction to this distribution
which is due to pairwise Hanbury Brown-Twiss correlations of produced gluons.Comment: 15 pages, 3 figures; version accepted for publicatio
Collisional energy loss above the critical temperature in QCD
We compute the collisional energy loss for a heavy quark above the critical
temperature in Quantum ChromoDynamics (QCD). We work in the semi Quark-Gluon
Plasma, which assumes that this region is dominated by the non-trivial holonomy
of the thermal Wilson line. Relative to the result to leading order in
perturbation theory, at a fixed value of the coupling constant we generically
we find that collisional energy loss is suppressed by powers of the Polyakov
loop, l < 1. For small values of the loop, this suppression is linear for the
scattering off of light quarks, and quadratic for the scattering off of gluons,
or for Compton scattering.Comment: 19 pages, 4 figure
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