Search for solar axions produced by Compton process and bremsstrahlung using the resonant absorption and axioelectric effect

Abstract

The search for resonant absorption of Compton and bremsstrahlung solar axions by ${}^{169}$Tm nuclei have been performed. Such an absorption should lead to the excitation of low-lying nuclear energy level: $A{+}^{169}$Tm ${\to }^{169}$Tm${}^{\ast }$ ${\to }^{169}$Tm $+\gamma$ (8.41 keV). Additionally the axio-electric effect in silicon atoms is sought. The axions are detected using a Si(Li) detectors placed in a low-background setup. As a result, a new model independent restrictions on the axion-electron and the axion-nucleon coupling: $g_{Ae}\times |g_{AN}^0+g_{AN}^3|\le 2.1\times 10^{-14}$ and the axion-electron coupling constant: $|g_{Ae}|\le 2.2\times 10^{-10}$ has been obtained. The limits leads to the bounds $m_A\le$ 7.9 eV and $m_A\le$ 1.3 keV for the mass of the axion in the DFSZ and KSVZ models, respectively ($90\%$ C.L.).

Comments: 6 pages, 3 figures, contributed to the 9th Patras Workshop on Axions, WIMPs and WISPs, Mainz, June 24-28, 2013