Synchrotron radiation and pair creation of massless charges in magnetic field

TL;DR

This paper investigates the behavior of synchrotron radiation and pair creation for massless charges in magnetic fields, deriving universal spectral formulas in a regime where traditional approximations break down.

Contribution

It introduces a new analytical approach to describe radiation and pair creation of massless charges in strong magnetic fields, revealing universal spectral features.

Findings

Derived simple expressions for synchrotron radiation spectra of massless charges.

Obtained pair creation probability distributions with universal spectral shapes.

Identified scaling properties in the high Landau level regime.

Abstract

We study the massless limit in synchrotron radiation and one-photon pair creation in magnetic field. In this limit Schwinger critical field $H_0=m^2c^3/(e\hbar)$ tends to zero, so two characteristic quantum parameters $\eta=H/H_0,\;\chi=\eta E/mc^2$ are infinite, and the standard approximations used in analytical calculations fail. Applying Schwinger's proper time methods we derive simple expressions for synchrotron radiation spectra emitted by massless charges of spins $s=0,\,1/2$ and the pair creation probability distribution in the quasiclassical (high Landau levels) regime exhibiting simple scaling properties and possessing universal spectral shapes.