Dynamical Correlation Theory for an Escape Process

A dynamical theory which incorporates the electron-electron correlations and the effects of external magnetic fields for an electron escaping from a helium surface is presented. The degrees of freedom in the calculation of the escape rate is reduced from $3N$ to 3 as compared with other approach. Explicit expressions for the escape rate in various situations are obtained. In particular, in the weak parallel magnetic field limit the tunneling rate has an exponential dependence quadratic with magnetic field strength and an unusual exponential increase linear with temperature.