Vector Meson Dominance and $g_{\rho \pi \pi }$ at Finite Temperature from QCD Sum Rules

Abstract

A Finite Energy QCD sum rule at non-zero temperature is used to determine the $q^2$- and the T-dependence of the $\rho \pi \pi$ vertex function in the space-like region. A comparison with an independent QCD determination of the electromagnetic pion form factor $F_{\pi }$ at $T\ne 0$ 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 $g_{\rho \pi \pi }(q^2,T)$ vanishes at the critical temperature $T_c$, independently of $q^2$. Also, by extrapolating the $\rho \pi \pi$ form factor to $q^2=0$, it is found that the pion radius increases with increasing $T$, and it diverges at $T=T_c$.

7 pages, Latex, 3 figures to be delivered from the authors by request, to appear in Phys. Lett. B

References in corpus (4)

• The Phase Transition to the Quark Gluon Plasma: Recent Results from Lattice Calculations
• Pions at Finite Temperature from QCD Sum Rules
• Electromagnetic pion form factor at finite temperature
• Comment on current correlators in QCD at finite temperature

Cited by in corpus (11)

• Charmonium in the vector channel at finite temperature from QCD sum rules
• Heavy-light quark pseudoscalar and vector mesons at finite temperature
• Rho-meson resonance broadening in QCD at finite temperature
• (Pseudo)Scalar Charmonium in Finite Temperature QCD
• Pion-Nucleon coupling at finite temperature
• QCD determination of the axial-vector coupling of the nucleon at finite temperature
• Axial anomaly, vector meson dominance and ${\pi }^0\to \gamma \gamma$ at finite temperature
• QCD sum rules and thermal properties of Charmonium in the vector channel
• The $\rho$ Meson and the Thermal Behavior of an Effective Hadronic Coupling Constant
• T-Dependent Dyson- Schwinger Equation In IR Regime Of QCD: The Critical Point
• Vector Meson Dominance, Axial Anomaly and the Thermal behavior of $g_{\rho \omega \pi }(T)$