학술논문
Direct high-precision measurement of the mass difference of $^{77}$As-$^{77}$Se related to neutrino mass determination
Document Type
Working Paper
Author
Ge, Z.; Eronen, T.; Ramalho, M.; de Roubin, A.; Nesterenko, D. A.; Kankainen, A.; Beliuskina, O.; de Groote, R.; Geldhof, S.; Gins, W.; Hukkanen, M.; Jokinen, A.; Koszorús, Á.; Kotila, J.; Kostensalo, J.; Moore, I. D.; Pirinen, P.; Raggio, A.; Rinta-Antila, S.; Sevestrean, V. A.; Suhonen, J.; Virtanen, V.; Zadvornaya, A.
Source
Subject
Language
Abstract
The first direct determination of the ground-state-to-ground-state ${\beta^{-}}$-decay $Q$-value of $^{77}$As to $^{77}$Se was performed by measuring their atomic mass difference utilizing the double Penning trap mass spectrometer, JYFLTRAP. The resulting $Q$-value is 684.463(70) keV, representing a remarkable 24-fold improvement in precision compared to the value reported in the most recent Atomic Mass Evaluation (AME2020). With the significant reduction of the uncertainty of the ground-state-to-ground-state $Q$-value and knowledge of the excitation energies in $^{77}$Se from $\gamma$-ray spectroscopy, the ground-state-to-excited-state $Q$-value of the transition $^{77}$As (3/2$^{-}$, ground state) $\rightarrow$ $^{77}$Se$^{*}$ (5/2$^{+}$, 680.1035(17) keV) was refined to be 4.360(70) keV. We confirm that this potential low $Q$-value ${\beta^{-}}$-decay transition for neutrino mass determination is energetically allowed at a confidence level of about 60$\sigma$. Nuclear shell-model calculations with two well-established effective Hamiltonians were used to estimate the partial half-life for the low $Q$-value transition. The half-life was found to be of the order of 10$^{9}$ years for this first-forbidden non-unique transition, which rules out this candidate a potential source for rare-event experiments searching for the electron antineutrino mass.
Comment: 8 pages, 4 figures
Comment: 8 pages, 4 figures