Plasmon Decay: From QED to QCD

Upon using the same theoretical framework, I describe two interesting decay processes: the electromagnetic plasmon decay into neutrinos, which can be the dominant cooling mechanism for red giants and white dwarfs, and the gluonic plasmon decay into quarks, which can be measured in ultra-relativistic heavy-ion collisions.Comment: 6 pages, 2 PostScript figures included (Talk given at the 3rd Workshop on Thermal Field Theories and their Applications, Banff, Canada, August 1993

Thermal Field Theory and Infinite Statistics

We construct a quantum thermal field theory for scalar particles in the case of infinite statistics. The extension is provided by working out the Fock space realization of a "quantum algebra", and by identifying the hamiltonian as the energy operator. We examine the perturbative behavior of this theory and in particular the possible extension of the KLN theorem, and argue that it appears as a stable structure in a quantum field theory context.Comment: 25 pp, INLN 92/16, ENSLAPP-A-372/9

Thermal quark production in pure glue and quark gluon plasmas

We calculate production rates for massless $(u,d)$ and massive $(s,c,b)$ quarks in pure glue and quark gluon plasmas to leading order in the strong coupling constant $g$. The leading contribution comes from gluon decay into $q\bar q$ pairs, using a thermal gluon propagator with finite thermal mass and damping rate. The rate behaves as $\alpha_S^2(\ln 1/\alpha_S)^2 T^4$ when $m, \alpha_S \rightarrow 0$ and depends linearly on the transverse gluon damping rate for all values of the quark mass $m$. The light quark ($u$, $d$, $s$) chemical equilibration time is approximately 10-100 $T^{-1}$ for $g=$2-3, so that quarks are likely to remain far from chemical equilibrium in ultrarelativistic nuclear collisions.Comment: 7 pages, 5 figures (available upon request), CERN preprint CERN-TH-6882/9

Pre-equilibrium dileptons look thermal

The dilepton mass distribution from pre-equilibrium matter in ultrarelativistic nuclear collisions is indistinguishable from a thermally produced distribution.Comment: CERN-TH.6813/93, 3 pages (latex) plus 1 figure (uuencoded postscript file

Thermal quark production in ultra-relativistic nuclear collisions

We calculate thermal production of u, d, s, c and b quarks in ultra-relativistic heavy ion collisions. The following processes are taken into account: thermal gluon decay (g to ibar i), gluon fusion (g g to ibar i), and quark-antiquark annihilation (jbar j to ibar i), where i and j represent quark species. We use the thermal quark masses, $m_i^2(T)\simeq m_i^2 + (2g^2/9)T^2$, in all the rates. At small mass ($m_i(T)<2T$), the production is largely dominated by the thermal gluon decay channel. We obtain numerical and analytic solutions of one-dimensional hydrodynamic expansion of an initially pure glue plasma. Our results show that even in a quite optimistic scenario, all quarks are far from chemical equilibrium throughout the expansion. Thermal production of light quarks (u, d and s) is nearly independent of species. Heavy quark (c and b) production is quite independent of the transition temperature and could serve as a very good probe of the initial temperature. Thermal quark production measurements could also be used to determine the gluon damping rate, or equivalently the magnetic mass.Comment: 14 pages (latex) plus 6 figures (uuencoded postscript files); CERN-TH.7038/9

Etude perturbative en theorie quantique des champs a temperature finie : application a l'emission de paires de leptons par un plasma de quarks et de gluons

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc