Positronium decay in a circular polarized laser field

TL;DR

This paper calculates how intense circularly polarized laser fields significantly extend the lifetime of positronium, with potential implications for high harmonic generation, by analyzing decay processes and separating Coulomb and laser effects.

Contribution

It introduces a factorization approach to analyze positronium decay in strong laser fields, revealing dramatic lifetime increases under specific laser conditions.

Findings

Positronium lifetime increases by up to 10^8 times in certain laser fields.

The factorization method effectively separates Coulomb and laser effects.

Results align with Schrödinger equation solutions.

Abstract

We calculate the lifetime of both the o-Ps and the p-Ps positronium annihilation decay $ Ps\to\gamma\gamma$ in the strong circular polarized laser field. We take a strategy of the factorization to separate the effects caused by the Coulomb interaction and the strong laser field interaction. It is factorized in the time direction but not in the space direction. Our results show that in the laser with long wavelength and high intensity, the lifetimes of those Ps states are dramatically increased. For $\rm CO_2$ laser with $10\, \mu m$ wavelength and $10^{13} W/cm^2$ intensity, lifetime of the spin-single positronium is increased by $10^8$ times. Our result is consistent with those obtained by solving the Sch{\"{o}}dinger equation. This effect may be useful for the high harmonic generation(HHG) effects provided with the Ps\cite{keitel2004}.