2 research outputs found
The Pion Decay Constants and the Rho-Meson Mass at Finite Temperature in the Hidden Local Symmetry
We study the temperature dependence of the pion decay constant and rho-meson
mass in the hidden local symmetry model at one loop. Using the standard
imaginary time formalism, we include the thermal effect of rho meson as well as
that of pion. We show that the pion gives a dominant contribution to the pion
decay constant and rho-meson contribution slightly decreases the critical
temperature. The rho-meson pole mass increases as T^4/m_\rho^2 at low
temperature dominated by the pion-loop effect. At high temperature, although
the pion-loop effect decreases the rho-meson mass, the rho-loop contribution
overcomes the pion-loop contribution and rho-meson mass increases with
temperature. We also show that the conventional parameter a is stable as the
temperature increases.Comment: We added a comment on the correction to the rho-meson mass from the
omega-pi loop. This is the final version to be published in Phys. Rev. D. 19
pages (LaTeX-RevTeX), 7 PostScript figure
Chiral Phase Transition of QCD at Finite Temperature and Density from Schwinger-Dyson Equation
We study the chiral phase transition of QCD at finite temperature and density
by numerically solving Schwinger-Dyson equation for the quark propagator with
the improved ladder approximation in the Landau gauge. Using the solution we
calculate a pion decay constant from a generalized version of Pagels-Stokar
formula. Chiral phase transition point is determined by analyzing an effective
potential for the quark propagator. We find solutions for which chiral symmetry
is broken while the value of the effective potential is larger than that for
the chiral symmetric vacuum. These solutions correspond to meta-stable states,
and the chiral symmetric vacuum is energetically favored. We present a phase
diagram on the general temperature--chemical potential plane, and show that
phase transitions are of first order in wide range.Comment: 23 pages (LaTeX-RevTeX), 14 PostScript figure