1,341 research outputs found
HTL quasiparticle picture of the thermodynamics of QCD
Starting from a nonperturbative expression for entropy and density obtained
from -derivable two-loop approximations to the thermodynamic potential, a
quasiparticle model for the thermodynamics of QCD can be developed which
incorporates the physics of hard thermal loops and leads to a reorganization of
the otherwise ill-behaved thermal perturbation theory through order
. Some details of this reorganization are discussed and the
differences to simpler quasiparticle models highlighted. A comparison with
available lattice data shows remarkable agreement down to temperatures of .Comment: Talk given at the International Conference on Statistical QCD,
Bielefeld, Germany, August 26--30, 2001. 10 pages LATEX, 7 figure
HTL-resummed thermodynamics of hot and dense QCD: An update
We review the proposal to resum the physics of hard thermal loops in the
thermodynamics of the quark-gluon plasma through nonperturbative expressions
for entropy and density obtained from a Phi-derivable two-loop approximation. A
comparison with the recently solved large-N_f limit of hot QCD is performed,
and some updates, in particular on quark number susceptibilities, are made.Comment: 10 pages, 6 figures. To appear in the proceedings of Strong and
Electroweak Matter (SEWM 2002), Heidelberg, Germany, 2-5 Oct 2002. v2: 1 typo
and 2 references update
A new anomalous contribution to the central charge of the N=2 monopole
We calculate the one-loop corrections to the mass and central charge of the
BPS monopole in N=2 super-Yang-Mills theory in 3+1 dimensions using a
supersymmetry-preserving version of dimensional regularization adapted to
solitons. In the renormalization scheme where previous studies have indicated
vanishing quantum corrections, we find nontrivial corrections that we identify
as the 3+1 dimensional analogue of the anomaly in the conformal central charge
of the N=1 supersymmetric kink in 1+1 dimensions. As in the latter case, the
associated contribution to the ordinary central charge has exactly the required
magnitude to preserve BPS saturation at the one-loop level. It also restores
consistency of calculations involving sums over zero-point energies with the
low-energy effective action of Seiberg and Witten.Comment: 1+10 pages. v3: version to appear in Physics Letters B (more precise
title and abstract, additional explanations in the text concerning the nature
of the anomaly involved
- …