Semiclassical Treatment of Induced Schwinger Processes at Finite Temperature

We consider induced pair production in an external field at finite temperature. One-loop correction to the Green function of a meson is calculated semiclassically within the framework of saddle-point analysis of Schwinger proper time integrals. This correction appears to be exponentially small in terms of inverse temperature dependence. Low-temperature limit is shown to be in full agreement with previously obtained zero-temperature results. The corrections in the low-temperature limits are estimated up to the leading exponential and pre-exponential terms. Comparison is made to earlier calculations of vacuum decay.