标题： 通过时空光学涡旋脉冲生成具有横向轨道角动量的$γ$光子和粒子对 显示英文标题

标题： Generation of $γ$-photons and pairs with transverse orbital angular momentum via spatiotemporal optical vortex pulse

摘要： 我们通过携带内在横向轨道角动量（TOAM）的强时空光学涡旋（STOV）脉冲与高能电子束的正面对撞，生成具有外在横向轨道角动量（TOAM）的准直$\gamma$-光子和粒子对。 发现 STOV 脉冲的 TOAM 几乎不变，并且在质心系（CMF）中 TOAM 是守恒的。 此外，当高能电子束的初始位置不同时，在 CMF 和实验室系（LF）中粒子的 TOAM 表现出二象性。 此外，随着 STOV 脉冲的拓扑荷增加，CMF 中$\gamma$-光子的 TOAM 增加，而正电子的 TOAM 减少，而在 LF 中，$\gamma$-光子和正电子的 TOAM 都减少。 并且在相同脉冲强度下的结果优于在相同脉冲能量下的结果。 高能电子的初始能量增加会导致在两个框架中$\gamma$-光子和正电子的 TOAM 增强。 具有 TOAM 的$\gamma$-光子和电子/正电子作为一种新的自由度，可能在光通信、天体物理学和纳米材料等领域有广泛的应用。 显示英文摘要

摘要： We present the generation of well-collimated $\gamma$-photons and pairs with extrinsic transverse orbital angular momentum (TOAM) through the head-on collision of an intense spatiotemporal optical vortex (STOV) pulse carrying intrinsic TOAM with a high-energy electron beam. It is found that the TOAM of STOV pulse remains almost unchanged, and the TOAM is conserved in the center-of-mass frame (CMF). Moreover, there exhibits duality for particles TOAM in the CMF and laboratory frame (LF) when the initial location of high-energy electron beam is different. Furthermore, the TOAM of $\gamma$-photons in the CMF increases while that of positrons decreases as the topological charge of STOV pulse increases, whereas in the LF, the TOAM of both $\gamma$-photons and positrons decreases. And the result under the same pulse intensity is better than that under the same pulse energy. The increase in the initial energy of high-energy electrons leads to an enhancement of the TOAM for both $\gamma$-photons and positrons in both frames. $\gamma$-photons and electrons/positrons with TOAM as a new degree of freedom maybe have an extensive applications in optical communication, astrophysics and nanomaterials and so on.