Minicharged particles search by strong laser pulse-induced vacuum polarization effects

TL;DR

This paper explores how laser-induced vacuum polarization effects can be used to search for minicharged particles, potentially excluding new parameter space regions with moderate laser intensities and polarimetric techniques.

Contribution

It demonstrates that contemporary laser and polarimetric methods can probe untested regions for minicharged particles by analyzing vacuum birefringence and dichroism effects.

Findings

Polarimetric detection can exclude new parameter space regions.

Gaussian wave profile influences polarization effects.

Vacuum dichroism depends on minicharge properties.

Abstract

Laser-based searches of the yet unobserved vacuum birefringence might be sensitive for very light hypothetical particles carrying a tiny fraction of the electron charge. We show that, with the help of contemporary techniques, polarimetric investigations driven by an optical laser pulse of moderate intensity might allow for excluding regions of the parameter space of these particle candidates which have not been discarded so far by laboratory measurement data. Particular attention is paid to the role of a Gaussian wave profile. It is argued that, at energy regimes in which the vacuum becomes dichroic due to these minicharges, the transmission probability of a probe beam through an analyzer set crossed to the initial polarization direction will depend on both the induced ellipticity as well as the rotation of the initial polarization plane. The weak and strong field regimes, relative to the attributes of these minicharged particles, and the relevance of the polarization of the strong field are investigated.