Solar Production of Ultralight Bosons

Abstract

This chapter will spotlight axions produced in the core of the Sun. A first focus will be put on the production mechanism for axions in the solar interior through coupling of axions to photons via the Primakoff effect as well as their interactions with electrons. In addition to the axion production, the axion-to-photon conversion probability is a crucial quantity for solar axion searches (also referred to as helioscopes) and determines the expected number of photons from solar axion conversion that are detectable in a ground-based search. After these basic considerations, the helioscope concept will be detailed, and past, current, and future experimental realizations of axion helioscopes will be discussed. This includes the analysis used to aim at axion detection and upper limit calculations in case no signal above background is detected in experimental data. For completeness, alternative approaches other than traditional helioscopes to search for solar axions are discussed.