965 research outputs found
Two-flavor condensates in chiral dynamics: temperature and isospin density effects
Isospin density and thermal corrections for several condensates are
discussed, at the one-loop level, in the frame of chiral dynamics with pionic
degrees of freedom. The evolution of such objects give an additional insight
into the condensed-pion phase transition, that occurs basically when
|\mui|>m_\pi, being |\mui| the isospin chemical potential. Calculations are
done in both phases, showing a good agreement with lattice results for such
condensates.Comment: 9 pages, 10 figure
Thermal Renormalons in Scalar Field Theory
In the frame of the scalar theory , we explore the occurrence of
thermal renormalons, i. e. temperature dependent singularities in the Borel
plane. The discussion of a particular renormalon type diagram at finite
temperature, using Thermofield Dynamics, allows us to establish that these
singularities actually get a temperature dependence. This dependence appears in
the residues of the poles, remaining their positions unchanged with
temperature.Comment: 12 pages, 3 figures, uses feynMF. Minor correction
Finite Temperature QCD Sum Rules: a Review
The method of QCD sum rules at finite temperature is reviewed, with emphasis
on recent results. These include predictions for the survival of charmonium and
bottonium states, at and beyond the critical temperature for de-confinement, as
later confirmed by lattice QCD simulations. Also included are determinations in
the light-quark vector and axial-vector channels, allowing to analyse the
Weinberg sum rules, and predict the dimuon spectrum in heavy ion collisions in
the region of the rho-meson. Also in this sector, the determination of the
temperature behaviour of the up-down quark mass, together with the pion decay
constant, will be described. Finally, an extension of the QCD sum rule method
to incorporate finite baryon chemical potential is reviewed.Comment: Minor typos corrected. To be published in the review section of
Advances in High Energy Physic
- …