New limit on the mass of 9.4-keV solar axions emitted in an M1 transition in $^{83}$Kr nuclei

TL;DR

This paper reports a new experimental upper limit on the mass of solar axions emitted during a specific nuclear transition in krypton-83, improving constraints on axion properties.

Contribution

The study provides the first model-independent upper limit on axion-nucleon couplings and sets a new upper bound on the hadronic axion mass at 130 eV.

Findings

Upper limit on axion-nucleon coupling |g_3 - g_0| ≤ 1.69×10^{-6}

New upper limit on axion mass m_A ≤ 130 eV (95% C.L.)

Experimental constraints improve previous bounds on solar axions.

Abstract

A search for resonant absorption of the solar axion by $^{83}\rm{Kr}$ nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the combination of isoscalar and isovector axion-nucleon couplings $|g_3-g_0|\leq 1.69\times 10^{-6}$ allowed us to set the new upper limit on the hadronic axion mass of $m_{A}\leq 130$ eV (95\% C.L.) with the generally accepted values $S$=0.5 and $z$=0.56.