Effect of Pions in Cosmic Rays

TL;DR

This paper explores how pions influence cosmic ray propagation, particularly gamma-ray spectra, through vacuum polarization and quark condensates, with potential implications for astrophysical observations.

Contribution

It introduces the effects of pions and quark condensates on gamma-ray propagation, highlighting their possible impact on astrophysical phenomena.

Findings

Pion-photon mixing causes deviations in gamma-ray spectra.

Effects are negligible for laboratory experiments but relevant for cosmic observations.

Potential observable signatures in TeV gamma-ray range from galactic centers.

Abstract

The effects of pions for vacuum polarization in background magnetic fields are considered. The effects of quark condensates is also briefly addresses. Although these effects are out of the measurement accuracy of laboratory experiments they may be relevant for gamma-ray burst propagation. In particular, for emissions from the center of the galaxy, we show that the mixing between the neutral pion and photons results in a deviation of the gamma-ray spectrum from the standard power-law in the TeV range.