arXiv subjects

M. S. Fetea

Publications and source records attributed to M. S. Fetea.

3 recordsLinked to original sources

arXiv1997

The $ρ$ Meson and the Thermal Behavior of an Effective Hadronic Coupling Constant

Vector Meson Dominance ideas together with a Finite Energy QCD sum rule allows for the determination of the $q^{2}$- and the $T$- dependence of the effective hadronic coupling constant $g_{ρππ}$ in the space-like region. It turns out that $g_{ρππ}(q^{2},T)$ vanishes at the critical temperature $T_{c}$, independently of $q^{2}$. A comparison with a previous independent QCD determination of the electromagnetic pion form factor at finite temperature supports the validity of Vector Meson Dominance at finite temperature. We find also thet the pion radius increases with $T$, having a divergent behavior at $T_{c}$.

hep-ph↗

arXiv1997

Vector Meson Dominance and $g_{ρππ}$ at Finite Temperature from QCD Sum Rules

A Finite Energy QCD sum rule at non-zero temperature is used to determine the $q^2$- and the T-dependence of the $ρππ$ vertex function in the space-like region. A comparison with an independent QCD determination of the electromagnetic pion form factor $F_π$ at $T \neq 0$ indicates that Vector Meson Dominance holds to a very good approximation at finite temperature. At the same time, analytical evidence for deconfinement is obtained from the result that $g_{ρππ}(q^{2},T)$ vanishes at the critical temperature $T_c$, independently of $q^{2}$. Also, by extrapolating the $ρππ$ form factor to $q^2 = 0$, it is found that the pion radius increases with increasing $T$, and it diverges at $T=T_c$.

hep-ph↗

arXiv1996

Pions at Finite Temperature from QCD Sum Rules

The temperature corrections to the current algebra Gell-Mann, Oakes, and Renner (GMOR) relation in $SU(2)\otimes SU(2)$ are investigated in the framework of QCD sum rules. There are no corrections at leading order in the quark masses. At the next to leading order we find corrections of the form $m_{q}^2\; T^{2}$, which are small except near the critical temperature. As a by-product we obtain the temperature behaviour of the pion mass, which is essentially constant, except near the critical temperature where it increases with $T$.

hep-ph↗