Quantum-stochasticity-induced asymmetry in the angular distribution of electrons in a quasiclassical regime

Impacts of quantum stochasticity on the dynamics of an ultrarelativistic electron beam head-on colliding with a linearly polarized ultraintense laser pulse are theoretically investigated in a quasiclassical regime. Generally, the angular distribution of the electron beam keeps symmetrically in transverse directions in this regime, even under the ponderomotive force of the laser pulse. Here we show that under certain conditions an asymmetric angular distribution of the electron beam arises due to the quantum stochasticity effect, via simulations employing Landau-Lifshitz equation, quantum-modified Landau-Lifshitz equation, and quantum stochastic radiation reaction forms, to describe the radiative electron dynamics. The asymmetry is robust against a variety of laser and electron parameters, providing an experimentally detectable signature for the nature of quantum stochasticity of photon emission with laser and electron beams currently available.