Polarized QED cascades
Polarized QED cascades
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DOI：
10.1088/1367-2630/abf584
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发表时间：
2020-10
影响因子：
3.3
通讯作者：
D. Seipt;C. Ridgers;D. Del Sorbo;Alec G. R. Thomas
中科院分区：
文献类型：
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作者：
D. Seipt;C. Ridgers;D. Del Sorbo;Alec G. R. Thomas
通过在强场QED过程中考虑电子、正电子和光子的自旋和极化，我们发现在超强激光场中QED级联的增长率可以大大降低.虽然这意味着产生的粒子更少，但我们也发现它们是高度极化的。我们进一步发现，粒子光谱的高能量尾部的极化与Sokolov-Ternov理论的预期相反，这不能仅仅通过考虑对产生过程中的自旋不对称性来解释，但结果显着从“自旋离散”。我们采用一个动力学方程的方法的电子，正电子和光子的分布，他们每个人的自旋/偏振分辨，与量子电动力学的光子发射和对生产的影响建模的自旋/偏振相关的玻尔兹曼型碰撞算子。对于光子种子级联，根据光子偏振，我们发现在级联发展的早期阶段，粒子生产过剩或短缺，这提供了一条通往受控实验的道路。在本文中，我们专注于旋转电场的配置，这代表了一个理想化的模型，并允许一个简单的解释所观察到的效果。
By taking the spin and polarization of the electrons, positrons and photons into account in the strong-field QED processes of nonlinear Compton emission and pair production, we find that the growth rate of QED cascades in ultra-intense laser fields can be substantially reduced. While this means that fewer particles are produced, we also found them to be highly polarized. We further find that the high-energy tail of the particle spectra is polarized opposite to that expected from Sokolov–Ternov theory, which cannot be explained by just taking into account spin-asymmetries in the pair production process, but results significantly from ‘spin-straggling’. We employ a kinetic equation approach for the electron, positron and photon distributions, each of them spin/polarization-resolved, with the QED effects of photon emission and pair production modelled by a spin/polarization dependent Boltzmann-type collision operator. For photon-seeded cascades, depending on the photon polarization, we find an excess or a shortage of particle production in the early stages of cascade development, which provides a path towards a controlled experiment. Throughout this paper we focus on rotating electric field configuration, which represent an idealized model and allows for a straightforward interpretation of the observed effects.