Quantum-mechanical approach to the laser-assisted vacuum decay

The quantum-field-theoretical problem of the vacuum decay into electron-positron pairs induced by external force fields is mapped onto the framework of a quantum-mechanical scattering process. This mapping permits us to generalize the Hund conjecture, which relates the long-time pair-creation rate for a static and spatially localized electric field to the transmission coefficient, to general space-time dependent forces that can induce multiphoton transitions. This leads to conceptual as well as computational simplifications as the vacuum's decay rate can be obtained from the laser-assisted scattering of quantum-mechanical wave packets with the force field. Using this mapping we find an analytical expression for the pair-creation rate for the case where the laser's polarization direction is perpendicular to the supercritical static force field.