High-energy γ -photon polarization in nonlinear Breit-Wheeler pair production and γ polarimetry

• Published in: Physical review research Vol. 2; no. 3; p. 032049
• Main Authors: Wan, Feng, Wang, Yu, Guo, Ren-Tong, Chen, Yue-Yue, Shaisultanov, Rashid, Xu, Zhong-Feng, Hatsagortsyan, Karen Z., Keitel, Christoph H., Li, Jian-Xing
• Format: Journal Article
• Language: English
• Published: American Physical Society 27-08-2020
• ISSN: 2643-1564; 2643-1564
• DOI: 10.1103/PhysRevResearch.2.032049

The interaction of an unpolarized electron beam with a counterpropagating ultraintense linearly polarized laser pulse is investigated in the quantum radiation-dominated regime. We employ a semiclassical Monte Carlo method to describe spin-resolved electron dynamics, photon emissions and polarization, and pair production. Abundant high-energy linearly polarized γ photons are generated intermediately during this interaction via nonlinear Compton scattering, with an average polarization degree of more than 50%, further interacting with the laser fields to produce electron-positron pairs due to the nonlinear Breit-Wheeler process. The photon polarization is shown to significantly affect the pair yield by a factor of more than 10%. The considered signature of the photon polarization in the pair's yield can be experimentally identified in a prospective two-stage setup. Moreover, with currently achievable laser facilities the signature can serve also for the polarimetry of high-energy high-flux γ photons.