Vector meson dominance and g(rho pi pi) at finite temperature from QCD sum rules

Dominguez, CA; Fetea, MS; Loewe, M

Vector meson dominance and g(rho pi pi) at finite temperature from QCD sum rules

Date

1997

Authors

Dominguez, CA

Fetea, MS

Loewe, M

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 not equal 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. (C) 1997 Elsevier Science B.V.