Speaker
Description
Axion is a hypothetical pseudoscalar Nambu-Goldstone boson that was introduced as an extension to the Standard Model intended to solve the strong CP problem.
It also could be a possible solution for a series of other fundamental physics problems such as the the dark matter or photon ultratransparency of the Universe.
As the least model-dependent axion interaction is its interaction with a nuclei, the most promising reaction for axion search is the resonant absorption.
If an axion exists, the sun would be a strong source of axion radiation, produced by mainly the so-called ABC reactions (Atomic recombination and deexcitation, Bremsstrahlung and Compton). These reactions produce axions with energies in the keV range and thus their detection through resonant absorption requires a nuclide with low-energy magnetic type gamma-transition. An optimal nuclide fulfilling these requirements is $^{169}$Tm that has an M1 transition with energy of 8.41 keV with magnetic type transition fraction that could be estimated close to unity.
In this work we describe a novice technique of axion search with Tm-containing crystal $\rm{Tm}_3\rm{Al}_5\rm{O}_{12}$, a garnet that could be operated in the bolometric regime. A small sample of this crystal of 8.18 g has been already applied for axion search producing a new limit of the coupling constants: $|g_{A\gamma} (g^0_{AN} + g^3{AN} )| \leq 1.44 \times 10^{−14} GeV^{−1}$ and $|g_{Ae}( (g^0_{AN} + g^3{AN} )| \leq 2.81 \times 10^{−16}$.
