Speaker
Description
Direct production of electron-position pairs in photon collisions is one of the basic processes in the Universe. The electron-positron production $\gamma+\gamma$ to $e^+$ +$ e^-$ (linear Breit-Wheeler process) is the lowest threshold process in photon-photon interaction, controlling the energy release in Gamma Ray Bursts, Active Galactic Nuclei, black holes and other explosive phenomena [1]. It is also responsible for the TeV cutoff in the photon energy spectrum of extra-galactic sources. The linear Breit-Wheeler process has never been clearly observed in laboratory with important probability of matter creation [2].
Thanks to the recent progress in high-power laser sources it will be possible to create compact sources of intense $\gamma$-ray beams (few MeV) and to use them in new experiments allowing to observe and study the BW process in laboratory [3]. In this presentation, based on the kinematics of two photon collisions, we study the $e^+-e^-$ beam properties. In particular, we demonstrate a possibility for beaming of $e^+-e^-$ pairs in one particular direction, which may strongly facilitate the observation of the BW process [4]. We show that the pair beaming effect depends on the angle between photon beams and the energy of each beam. Moreover, the numerical simulations with the photon collision code TriLens [5] are in good agreement with the analytical model. Simulation results obtained with TriLens using optimized gamma beams to prepare experiments on future ultra-high intensities lasers like Apollon will be presented. With higher photon beam energies (>100 MeV) the beaming effect can be observed also for muon-pairs creation.
We acknowledge the financial support from the French National Research Agency (ANR) in the frame of "The Investments for the Future" Programme IdEx Bordeaux - LAPHIA (ANR-10-IDEX-03-02) - Project TULIMA. This work is partly supported by the Aquitaine Regional Council (project ARIEL).
[1] Ruffini, R. et al. Physics Reports, 487, 1-140 (2010).
[2] Bamber C. et al. Phys. Rev. D, 60, 092004 (1999).
[3] Ribeyre X. et al. Phys. Rev. E, 93 013201 (2016).
[4] Ribeyre X. et al., PPCF 59, 014024 (2017).
[5] Jansen O. et al., Submitted to JCP, arXiv:1608.01125 (2016).
