Speaker
Description
Double $\beta$ (2$\beta$) and double electron capture (ECEC) decays are active areas of research, and confirmation of a neutrinoless decay channel would identify the neutrino as a Majorana particle. The half-lives of these decay modes depend sensitively on the masses of the parent and daughter isotopes as the Q-value determines both the resonant enhancement of neutrinoless ECEC decays [1] and the available phase space in standard ECEC decays [2]. Many candidate isotopes for such decays have yet to be observed experimentally.
We measured the nuclear masses of $^{132}$Ba and $^{134}$Ba with the JYFLTRAP double Penning trap mass spectrometer via the Phase Imaging Ion Cyclotron Resonance (PI-ICR) technique. Stable barium ions were produced using a plasma discharge ion source, mass-separated with a magnetic dipole, and then bunched in the radio-frequency quadrupole trap (RFQ) before injection into JYFLTRAP. We present a mass measurement of a double electron capture (ECEC) decay candidate ($^{132}$Ba) and discuss its relevance to the resonantly enhanced neutrinoless ECEC decay mode, as well as an updated calculation of the available phase space in two-neutrino ECEC decay.
References:
[1] K. Blaum, et al., Neutrinoless double-electron capture. Rev. Mod. Phys. 92(4), 045007 (2020)
[2] J. Kotila, F. Iachello, Phase space factors for β$^+$β$^+$ decay and competing modes of double-β decay. Phys. Rev. C 87(2), 024313 (2013)