The process of resonant high-energy electron–positron pair production by an ultrarelativistic electron colliding with the field of an X-ray pulsar is theoretically investigated. Resonant kinematics of the process is studied in detail. Under the resonance condition, the intermediate virtual photon in the X-ray pulsar field becomes a real particle. As a result, the initial process of the second order in the fine structure constant effectively reduces into two successive processes of the first order: X-ray-stimulated Compton effect and X-ray-stimulated Breit–Wheeler process. For a high-energy initial electron all the final ultrarelativistic particles propagate in a narrow cone along the direction of the initial electron momentum. The presence of threshold energy for the initial electron which is of order of 100 MeV for 1-KeV-frequency field is shown. At the same time, the energy spectrum of the final particles (two electrons and a positron) highly depends on their exit angles and on the initial electron energy. This result significantly distinguishes the resonant process from the non-resonant one. It is shown that the resonant differential probability significantly exceeds the non-resonant one.

中文翻译：

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X射线脉冲星场中高能电子产生的共振超相对论电子-正电子对

理论上研究了超相对论性电子与X射线脉冲星场碰撞产生的高能共振电子-正电子对的过程。详细研究了该过程的共振运动学。在共振条件下，X射线脉冲星场中的中间虚拟光子变为真实粒子。结果，精细结构常数中的第二阶初始过程有效地减少为两个第一阶连续过程：X射线刺激的康普顿效应和X射线刺激的Breit-Wheeler过程。对于高能量的初始电子，所有最终的超相对论粒子都沿着初始电子动量的方向在一个狭窄的圆锥体中传播。示出了对于1-KeV频率场，初始电子的阈值能量的存在为100MeV。同时，最终粒子（两个电子和一个正电子）的能谱高度取决于它们的出射角和初始电子能。这一结果将共振过程与非共振过程区分开来。结果表明，谐振微分概率大大超过了非谐振微分概率。