Long-Lived Particles and the Quiet Sun

TL;DR

This paper explores how satellite observations of the Quiet Sun can detect long-lived particles from dark sector models, providing a novel method to probe regions of parameter space with specific decay lengths.

Contribution

It introduces the use of Quiet Sun MeV observations, especially from RHESSI, as a new probe for long-lived particles in dark sector models, complementing existing detection methods.

Findings

Quiet Sun observations can detect long-lived particles with decay lengths between the Sun's radius and the Earth.

Satellite instruments like RHESSI are sensitive to MeV-scale signals from long-lived particle decays.

The work connects astrophysical observations to recent dark sector model developments.

Abstract

The nuclear reaction network within the interior of the Sun is an efficient MeV physics factory, and can produce long-lived particles generic to dark sector models. In this work we consider the sensitivity of satellite instruments, primarily the RHESSI Spectrometer, that observe the Quiet Sun in the MeV regime where backgrounds are low. We find that Quiet Sun observations offer a powerful and complementary probe in regions of parameter space where the long-lived particle decay length is longer than the radius of the Sun, and shorter than the distance between the Sun and Earth. We comment on connections to recent model-building work on heavy neutral leptons coupled to neutrinos and high-quality axions from mirror symmetries.