Muon pair creation from positronium in a linearly polarized laser field

Abstract

Positronium decay into a muon-antimuon pair by virtue of the interaction with a superintense laser field of linear polarization is considered. The minimum laser intensity required amounts to a few ${10}^{22}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$ in the near-infrared frequency range. Within the framework of laser-dressed quantum electrodynamics, the total reaction rate is calculated and related to the cross section for field-free electron-positron annihilation into muons. The muons are created with ultrarelativistic energies and emitted under narrow angles along the laser propagation direction. The dynamical properties of the muons are interpreted in terms of a classical simple man's model for the production process. We show that the most promising setup for an experimental investigation of the process in the near future is based on the combination of upcoming superintense laser sources with envisaged positron accumulation techniques: It employs two counterpropagating laser beams impinging on a positronium target, where the advantage of the coherent electron-positron collisions becomes evident.