Search for axioelectric effect of 5.5 MeV solar axions using BGO detectors

A search for axioelectric absorption of solar axions produced in the $p + d \rightarrow {^3\rm{He}}+\gamma (5.5 \rm{MeV})$ reactions has been performed with a BGO detector placed in a low-background setup. A model-independent limit on an axion-nucleon and axion-electron coupling constant has been obtained: $| g_{Ae}\times g_{AN}^3|< 2.9\times 10^{-9}$ for 90% confidence level. The constrains of the axion-electron coupling have been obtained for hadronic axion with masses in (0.1 - 1) MeV range: $|g_{Ae}| \leq (1.4 - 9.7)\times 10^{-7}$.Comment: 6 pages, 4 figures, to be published in EPJ C. arXiv admin note: substantial text overlap with arXiv:1007.338

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

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 $\rightarrow ^{169}$Tm$^*$ $\rightarrow ^{169}$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: $g_{Ae}\times|g^0_{AN}+ g^3_{AN}|\leq 2.1\times10^{-14}$ and the axion-electron coupling constant: $|g_{Ae}| \leq 2.2\times 10^{-10}$ has been obtained. The limits leads to the bounds $m_{A}\leq$ 7.9 eV and $m_{A}\leq$ 1.3 keV for the mass of the axion in the DFSZ and KSVZ models, respectively ($90\%$ C.L.).Comment: 6 pages, 3 figures, contributed to the 9th Patras Workshop on Axions, WIMPs and WISPs, Mainz, June 24-28, 201

Constraints on the axion-electron coupling for solar axions produced by Compton process and bremsstrahlung

The search for solar axions produced by Compton ($\gamma+e^-\rightarrow e^-+A$) and bremsstrahlung-like ($e^-+Z \rightarrow Z+e^-+A$) 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 $^{169}\rm{Tm}$ was looked for: $A+^{169}$Tm $\rightarrow ^{169}$Tm$^*$ $\rightarrow ^{169}$Tm $+ \gamma$ (8.41 keV). The Si(Li) detector and $^{169}$Tm target installed inside the low-background setup were used to detect 8.41 keV $\gamma$-rays. As a result, a new model independent restriction on the axion-electron and the axion-nucleon couplings was obtained: $g_{Ae}\times|g^0_{AN}+ g^3_{AN}|\leq 2.1\times10^{-14}$. In model of hadronic axion this restriction corresponds to the upper limit on the axion-electron coupling and on the axion mass $g_{Ae}\times m_A\leq3.1\times10^{-7}$ eV (90% c.l.). The limits on axion mass are $m_A\leq$ 105 eV and $m_A\leq$ 1.3 keV for DFSZ- and KSVZ-axion models, correspondingly (90% c.l.).Comment: 7 pages, 4 figure

Searches for axioelectric effect of solar axions with BGO-scintillator and BGO-bolometer detectors

A search for axioelectric absorption of 5.5 MeV solar axions produced in the $p + d \rightarrow {^3\rm{He}}+\gamma~(5.5~ \rm{MeV})$ reaction has been performed with a BGO detectors. A model-independent limit on the product of axion-nucleon $g_{AN}^3$ and axion-electron $g_{Ae}$ coupling constants has been obtained: $| g_{Ae}\times g_{AN}^3|< 1.9\times 10^{-10}$ for 90\% C.L..Comment: 5 pages, 3 figures, Proceedings of the 10th Patras Workshop on Axions, WIMPs and WISP 29 June - 4 July 2014, CERN, Geneva, Switzerlan