Photon polarisation in light-by-light scattering: finite size effects
Abstract
We derive a simple expression for the photon helicity and polarisation-flip probabilities in arbitrary background fields, in the low energy regime. Taking the background to model a focused laser beam, we study the impact of pulse shape and collision geometry on the probabilities and on ellipticity signals of vacuum birefringence. We find that models which do not account for pulse duration can overestimate all signals in near head-on collisions by up to an order of magnitude. Taking pulse duration into account, the flip probability becomes relatively insensitive to both angular incidence and the fine details of the pulse structure.
Cite
@article{arxiv.1405.7291,
title = {Photon polarisation in light-by-light scattering: finite size effects},
author = {Victor Dinu and Tom Heinzl and Anton Ilderton and Mattias Marklund and Greger Torgrimsson},
journal= {arXiv preprint arXiv:1405.7291},
year = {2014}
}
Comments
10 pages, 9 jpg and pdf figures. Version 2: added references and extended discussion of ellipticity and collision angle dependence. Matches version to appear in PRD