Searching for minicharged particles via birefringence, dichroism and Raman spectroscopy of the vacuum polarized by a high-intensity laser wave

摘要

Absorption and dispersion of probe photons in the field of a high-intensitycircularly polarized laser wave are investigated. The optical theorem isapplied for determining the absorption coefficients in terms of the imaginarypart of the vacuum polarization tensor. Compact expressions for the vacuumrefraction indices and the photon absorption coefficients are obtained invarious asymptotic regimes of interest. The outcomes of this analysis revealthat, far from the region relatively close to the threshold of the two-photonreaction, the birefringence and dichroism of the vacuum are small and, in somecases, strongly suppressed. On the contrary, in a vicinity of the region inwhich the photo-production of a pair occurs, these optical properties aremanifest with lasers of moderate intensities. We take advantage of such aproperty in the search of minicharged particles by considering high-precisionpolarimetric experiments. In addition, Raman-like electromagnetic wavesresulting from the inelastic part of the vacuum polarization tensor aresuggested as an alternative form for finding exclusion limits on thesehypothetical charge carriers. The envisaged parameters of upcominghigh-intensity laser facilities are used for establishing upper bounds on theminicharged particles.