The search for solar axions produced by Compton (γ+e−→e−+A) and bremsstrahlung-like (e−+Z→Z+e−+A) processes has been performed. The axion flux in the both cases depends on the axion-electron coupling constant. The resonant excitation of low-lying nuclear level of 169Tm was looked for: A+169Tm →169Tm∗→169Tm +γ (8.41 keV). The Si(Li) detector and 169Tm target installed inside the low-background setup were used to detect 8.41 keV γ-rays. As a result, a new model independent restriction on the axion-electron and the axion-nucleon couplings was obtained: gAe×∣gAN0+gAN3∣≤2.1×10−14. In model of hadronic axion this restriction corresponds to the upper limit on the axion-electron coupling and on the axion mass gAe×mA≤3.1×10−7 eV (90% c.l.). The limits on axion mass are mA≤ 105 eV and mA≤ 1.3 keV for DFSZ- and KSVZ-axion models, correspondingly (90% c.l.).
@article{arxiv.1101.2290,
title = {Constraints on the axion-electron coupling for solar axions produced by Compton process and bremsstrahlung},
author = {A. V. Derbin and A. S. Kayunov and V. N. Muratova and D. A. Semenov and E. V. Unzhakov},
journal= {arXiv preprint arXiv:1101.2290},
year = {2011}
}