Spin and polarization effects on the nonlinear Breit–Wheeler pair production in laser-plasma interaction. (15th July 2021)

• Record Type: Journal Article
• Authors: Song, Huai-Hang; Wang, Wei-Min; Li, Yan-Fei; Li, Bing-Jun; Li, Yu-Tong; Sheng, Zheng-Ming; Chen, Li-Ming; Zhang, Jie
• Is Part Of: New journal of physics. Volume 23:Number 7(2021)
• Publication Date: 2021-07-15
• Subjects: spin and polarization effects -- pair production -- strong-field QED -- laser-plasma interaction -- particle-in-cell simulation; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ac0dec
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: The spin effect of electrons/positrons ( e − / e + ) and polarization effect of γ photons are investigated in the interaction of two counter-propagating linearly polarized laser pulses of peak intensity 8.9 × 10 23 W cm −2 with a thin foil target. The processes of nonlinear Compton scattering and nonlinear Breit–Wheeler pair production based on the spin- and polarization-resolved probabilities are implemented into the particle-in-cell (PIC) algorithm by Monte Carlo methods. It is found from PIC simulations that the average degree of linear polarization of emitted γ photons can exceed 50%. This polarization effect leads to a reduced positron yield by about 10%. At some medium positron energies, the reduction can reach 20%. Furthermore, we also observe that the local spin polarization of e − / e + leads to a slight decrease of the positron yield about 2% and some anomalous phenomena about the positron spectrum and photon polarization at the high-energy range, due to spin-dependent photon emissions. Our results indicate that spin and polarization effects should be considered in calculating the pair production and laser-plasma interaction with the laser power of 10 PW to 100 PW classes.