Photon production by a quark gluon plasma

In this talk, I review the status of the calculation of the photon production rate in a hot quark-gluon plasma. Particular emphasis is given to the discussion of the various length scales of the problem.Comment: Based on talks given at Quark Matter 2001, January 2001, Stony Brook, USA and at 36th Rencontres de Moriond, March 2001, Les Arcs, France (4 pages LaTeX document, 3 postscript figures

The glasma initial state and JIMWLK factorization

We review recent work on understanding the next to leading order corrections to the classical fields that dominate the initial stages of a heavy ion collision. We have recently shown that the leading ln(1/x) divergences of these corrections to gluon multiplicities can be factorized into the JIMWLK evolution of the color charge density distributions.Comment: 4 pages, 2 figures. Talk given by T.L. at Strong and Electroweak Matter 2008 (SEWM08), August 26-29, 2008, Amsterdam, The Netherland

Are there monojets in high-energy proton-nucleus collisions?

We study high-energy proton-nucleus collisions within the Colour Glass Condensate framework, and compute the probabilities of having a definite number of scatterings in the nucleus with a momentum transfer larger than a given cut. Various properties of the distribution in the number of multiple scatterings are investigated, and we conclude that events with monojets are very unlikely, except for extreme values of the saturation scale Qs.Comment: 4 pages, 4 eps-figures. Talk given at Quark Matter 2006, Shanghai, 14-20 Nov. 200

Factorization in high energy nucleus-nucleus collisions

In this talk, we discuss the factorization of the logarithms of energy in the Color Glass Condensate framework.Comment: proceedings of the conference ISMD 2012, Kielce, Polan

Quark-antiquark production from classical fields and chemical equilibration

We compute by numerical integration of the Dirac equation the number of quark-antiquark pairs produced in the classical color fields of colliding ultrarelativistic nuclei. The backreaction of the created pairs on the color fields is not taken into account. While the number of qqbar pairs is parametrically suppressed in the coupling constant, we find that in this classical field model it could even be compatible with the thermal ratio to the number of gluons. After isotropization one could thus have quark-gluon plasma in chemical equilibrium.Comment: 4 pages, 6 figures, contribution to proceedings of Quark Matter 2005, Budapest, Aug 4-

Quark production in heavy ion collisions I. Formalism and boost invariant fermionic light-cone mode functions

We revisit the problem of quark production in high energy heavy ion collisions, at leading order in $\alpha_s$ in the color glass condensate framework. In this first paper, we setup the formalism and express the quark spectrum in terms of a set of mode functions of the Dirac equation. We determine analytically their initial value in the Fock-Schwinger gauge on a proper time surface $Q_s\tau_0\ll 1$, in a basis which makes manifest the boost invariance properties of this problem. We also describe a statistical algorithm to perform the sampling of the mode functions.Comment: 40 pages, 3 figures, alternate derivation in the new appendix

Production of quark pairs from classical gluon fields

We compute by numerical integration of the Dirac equation the number of quark-antiquark pairs produced in the classical color fields of colliding ultrarelativistic nuclei. Results for the dependence of the number of quarks on the strength of the background field, the quark mass and time are presented. We also perform several tests of our numerical method. While the number of qqbar pairs is parametrically suppressed in the coupling constant, we find that in this classical field model it could even be compatible with the thermal ratio to the number of gluons.Comment: 8 pages, 12 figures, contribution to the proceedings of the Quark Gluon Plasma Thermalization Workshop, Vienna, August 200