Neutrinos from muon-rich ultra high energy electromagnetic cascades: The MUNHECA code

An ultra high energy electromagnetic cascade, a purely leptonic process and initiated by either photons or e^±, can be a source of high energy neutrinos. We present a public python3 code, MUNHECA, to compute the neutrino spectrum by taking into account various QED processes, with the cascade developing either along the propagation in the cosmic microwave background in the high-redshift universe or in a predefined photon background surrounding the astrophysical source. The user can adjust various settings of MUNHECA, including the spectrum of injected high energy photons, the background photon field and the QED processes governing the cascade evolution. We improve the modeling of several processes, provide examples of the execution of MUNHECA and compare it with some earlier and more simplified estimates of the neutrino spectrum from electromagnetic cascades.由光子或正负电子（e^±）引发的纯轻子过程——超高能电磁级联，可作为高能中微子的产生源。我们公开了一款Python3代码MUNHECA，可通过考量各类量子电动力学（QED）过程计算中微子能谱；该级联既可以在高红移宇宙中沿宇宙微波背景传播时发展，也可在天体物理源周围预设的光子背景中演化。用户可对MUNHECA的各项设置进行调整，包括注入的高能光子能谱、背景光子场以及调控级联演化的量子电动力学过程。我们改进了若干过程的建模工作，提供了MUNHECA的运行示例，并将其与此前基于电磁级联得到的若干更为简化的中微子能谱估算结果进行了对比。