# A search for solar axion induced signals with COSINE-100

## TL;DR

This study used the COSINE-100 detector to search for solar axions, setting new upper limits on axion-electron coupling and excluding certain QCD axion mass ranges, but found no evidence of axion signals.

## Contribution

First search for solar axions with COSINE-100, establishing new upper limits on axion-electron coupling and constraining QCD axion mass models.

## Key findings

- No evidence of solar axions detected.
- Set a 90% CL upper limit on $g_{ae}$ at 1.70×10^{-11}.
- Excluded QCD axions heavier than 0.59 eV/c^2 (DFSZ) and 168.1 eV/c^2 (KSVZ).

## Abstract

We present results from a search for solar axions with the COSINE-100 experiment. We find no evidence of solar axion events from a data-set of 6,303.9 kg$\cdot$days exposure and set a 90\,\% confidence level upper limit on the axion-electron coupling, $g_{ae}$, at 1.70~$\times$~$10^{-11}$ for an axion mass less than 1\,keV/c$^2$. This limit excludes QCD axions heavier than 0.59\,eV/c$^2$ in the DFSZ model and 168.1\,eV/c$^2$ in the KSVZ model.