https://doi.org/10.1140/epja/s10050-024-01317-3
Regular Article - Experimental Physics
Direct high-precision measurement of the mass difference of 
As–Se related to neutrino mass determination
1
Department of Physics, University of Jyväskylä, P.O. Box 35, 40014, Jyväskylä, Finland
2
Centre d’Etudes Nucléaires de Bordeaux Gradignan, UMR 5797 CNRS/IN2P3, Université de Bordeaux, 19 Chemin du Solarium, CS 10120, 33175, Gradignan Cedex, France
3
KU Leuven, Instituut voor Kern-en Stralingsfysica, 3001, Leuven, Belgium
4
Department of Physics, University of Liverpool, L69 7ZE, Liverpool, UK
5
Finnish Institute for Educational Research, University of Jyväskylä, P.O. Box 35, 40014, Jyväskylä, Finland
6
Center for Theoretical Physics, Sloane Physics Laboratory Yale University, 06520-8120, New Haven, CT, USA
7
International Centre for Advanced Training and Research in Physics, P.O. Box MG12, 077125, Bucharest-Măgurele, Romania
8
Natural Resources, Natural Resources Institute Finland, Yliopistokatu 6B, 80100, Joensuu, Finland
9
Faculty of Physics, University of Bucharest, P.O. Box MG11, 405 Atomiştilor, 077125, Bucharest-Măgurele, Romania
10
“Horia Hulubei” National Institute of Physics and Nuclear Engineering, 30 Reactorului, POB MG-6, 077125, Bucharest-Măgurele, Romania
11
GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, 14000, Caen, France
12
University of Edinburgh, EH9 3FD, Edinburgh, UK
a
zhuang.z.ge@jyu.fi
b
tommi.eronen@jyu.fi
c
madeoliv@jyu.fi
x
jouni.t.suhonen@jyu.fi
Received:
5
February
2024
Accepted:
12
April
2024
Published online:
8
May
2024
The first direct determination of the ground-state-to-ground-state 
-decay Q-value of As to 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 Se from 
-ray spectroscopy, the ground-state-to-excited-state Q-value of the transition As (3/2
, ground state) 
Se
(5/2
, 680.1035(17) keV) was refined to be 4.360(70) keV. We confirm that this potential low Q-value -decay transition for neutrino mass determination is energetically allowed at a confidence level of about 60
. 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
years for this first-forbidden non-unique transition. Since the half-life of As is only 
2 days, usage of it as source for rare-event experiments searching for the electron antineutrino mass would be challenging.
© The Author(s) 2024
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
