Pion electromagnetic form factor at finite temperature.

Abstract

Temperature effects on the electromagnetic couplings of pions in hot hadronic matter are studied with an effective chiral Lagrangian. We show that the Ward-Takahashi identity is satisfied at nonzero temperature in the soft pion limit. The in-medium electromagnetic form factor of the pion is obtained in the timelike region and shown to be reduced in magnitude, especially near the vector-meson resonance region. Finally, we discuss the consequences of this medium effect on dilepton production from hot hadronic matter. {copyright} {ital 1996 The American Physical Society.}