# Collision of ultra-relativistic proton with strong magnetic field: production of ultra-high energy photons and neutrinos

## TL;DR

This paper introduces a new process called $pB$ involving ultra-high energy protons interacting with strong magnetic fields, leading to significant production of cosmic photons and neutrinos, especially in extreme astrophysical environments.

## Contribution

It proposes the $pB$ process as a novel mechanism for ultra-high energy particle production, extending current models of cosmic ray interactions in strong magnetic fields.

## Key findings

- The $pB$ process occurs when $ ext{γ}_p B
oughly 5 imes 10^{18}$ Gauss.
- Energy loss rate in $pB$ process exceeds synchrotron radiation by three orders.
- Potential occurrence in white dwarfs, neutron stars, and black hole atmospheres.

## Abstract

Proton-proton interaction and photo-hadronic interaction in cosmic accelerators are the two main channels for the production of cosmic ultra-high energy photons and neutrinos (TeV-PeV). In this Letter, we use FWW approach to obtain the production of cosmic ultra-high energy photons and neutrinos from the collision between UHE proton with magnetic field which could be considered as the virtualphoton in the rest frame of UHE proton. We name this as $pB$ process. The threshold for the occurrence of the $pB$ process is that the combination of the Lorentz factor of proton and the strength of the magnetic field is about $\gamma_p B \simeq 5\times 10^{18}$Gauss. Beyond this threshold, the rate of energy loss of proton due to the $pB$ process is about three orders higher than that due to the synchrotron radiation of proton in the same magnetic field. The $pB$ process might potentially happen in the atmosphere of white dwarfs, neutron stars or even that of stellar massive black holes.