标题： 逆向传播激光脉冲中的施温格对产生：确定体积因子 显示英文标题

标题： Schwinger pair production in counterpropagating laser pulses: Identifying volume factors

摘要： 我们研究了在两个反向传播的线性偏振激光脉冲组合中真空粒子对产生的非微扰过程，这些脉冲具有有限的空间范围。 通过局部恒定场近似（LCFA），我们计算了相应四维设置中的总粒子产率，并将其与简化低维情景所得的估计值进行比较。 在LCFA得到很好验证的区域内，我们研究了两个平面波脉冲的组合、驻电磁波以及空间均匀振荡场，并证明在这些三个近似层次中的每一个层次上，都可以通过乘以根据场参数适当选择的体积因子来准确预测实际粒子数。 我们给出了这些因子的显式表达式，提供了评估粒子产率的通用方法。 我们最终将空间均匀设置与四维情景联系起来的公式具有约$10\%$级别的相对不确定性。 本研究推导出的显式对应关系不仅证明了近似预测的相关性，还允许人们在不执行多维LCFA积分的情况下快速估算各种现实情景中的粒子数。 显示英文摘要

摘要： We investigate the nonperturbative process of vacuum pair production in a combination of two counterpropagating linearly polarized laser pulses of a finite spatial extent. By means of the locally-constant field approximation (LCFA), we calculate the total particle yield for the corresponding four-dimensional setup and compare it with the estimates obtained for simplified low-dimensional scenarios. Within the domain where the LCFA is well justified, we examine a combination of two plane-wave pulses, a standing electromagnetic wave, and a spatially uniform oscillating field and demonstrate that at each of these three levels of approximation, one can accurately predict the actual particle number by multiplying the results by properly chosen volume factors depending on the field parameters. We present closed-form expressions for these factors providing universal prescriptions for evaluating the particle yield. Our final formula connecting the spatially uniform setup with the four-dimensional scenario has a relative uncertainty of the level of $10\%$. The explicit correspondences deduced in this study not only prove the relevance of the approximate predictions, but also allow one to quickly estimate the number of pairs for various realistic scenarios without performing multidimensional LCFA integrations.