Collisional energy loss of a fast particle in a medium is mostly due to the medium polarization by the electromagnetic fields of the particle. A small fraction of energy is carried away by the Cherenkov radiation. In chiral medium there is an additional contribution to the energy loss due to induction of the anomalous current proportional to the magnetic field. It causes the particle to lose energy mostly in the form of the chiral Cherenkov radiation. We employ classical electrodynamics, adequate in a wide range of particle energies, to compute the collisional energy loss by a fast particle in a homogenous chiral plasma and apply the results to quark-gluon plasma and a Weyl semimetal. In the latter case photon spectrum is strongly enhanced in the ultraviolet and x-ray regions which makes it amenable to experimental investigation. Our main observation is that while the collisional energy loss in a nonchiral medium is a slow, at most logarithmic, function of energy $\varepsilon$, the chiral Cherenkov radiation is proportional to ${\varepsilon }^2$ when the recoil is neglected and to $\varepsilon$ when it is taken into account.

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碰撞能量损失和手性磁效应

快速粒子在介质中的碰撞能量损失主要是由于粒子的电磁场引起的介质极化。一小部分能量被切伦科夫辐射带走。在手性介质中，由于感应与磁场成正比的异常电流，对能量损失有额外的贡献。它导致粒子主要以手性的形式失去能量切伦科夫辐射。我们采用经典电动力学，适用于广泛的粒子能量范围，计算均匀手性等离子体中快速粒子的碰撞能量损失，并将结果应用于夸克-胶子等离子体和外尔半金属。在后一种情况下，光子光谱在紫外线和 X 射线区域中得到强烈增强，这使其适合进行实验研究。我们的主要观察是，虽然非手性介质中的碰撞能量损失是一个缓慢的，最多是对数的能量函数$\varepsilon$，手性切伦科夫辐射正比于 ${\varepsilon }^2$ 当后坐力被忽略并且 $\varepsilon$ 当它被考虑在内。