Speaker
Description
Stable isotope selenium-82 is a perspective object for double beta decay investigations and searches for neutrinoless transition. It is used as a 2-source in large-scale projects - NEMO-3, SuperNEMO, CUPID-0. In the recent experimental works [1,2] two-neutrino channel for 82Se was examined in order to determine nuclear mechanism of 22-decay. The question is whether contribution of the single lowest 1+ level dominates in the total transition amplitude, and SSD –mechanism takes place, or otherwise higher state dominates, that corresponds to HSD-mechanism. The effective method to distinguish these possibilities is to measure energy distribution of emitted electrons, which has different form for SSD and HSD mechanisms [3,4]. It should be noted that for 82Se the quantum numbers of intermediate nucleus 82Br ground state is 5-, so the first excited 1+ - state of 82Br should be taken into account. The energy spectra of electrons produced in 22-decay are calculated. For SSD mechanism the 82Se 22- amplitude is determined by the product of two nuclear matrix elements, where first excited low-lying 1+ state of 82Br is involved. Assumption has made, that the measurement of total intensity of two-neutrino process can give information on the value of these matrix elements, additional to the results, based on charge-exchange reactions study.
- R. Arnold et al , Eur. J. Phys. C, V. 78, 821 (2018)
- O. Azzolini et al, Phys. Rev. Lett. V. 123, P. 262501 (2019)
- Semenov S.V., Šimkovic F., Khruschev V.V., Domin P., Phys. Atom. Nucl. 2000,V.63, P. 1196 (2000)
- Šimkovic, F., Domin, P., Semenov S.V., . Phys. G., V. 27, P. 2233 (2001)
