A1 Journal article (refereed)
β− decay Q-value measurement of 136Cs and its implications for neutrino studies (2023)

Ge, Z., Eronen, T., de Roubin, A., Ramalho, M., Kostensalo, J., Kotila, J., Suhonen, J., Nesterenko, D. A., Kankainen, A., Ascher, P., Beliuskina, O., Flayol, M., Gerbaux, M., Grévy, S., Hukkanen, M., Husson, A., Jaries, A., Jokinen, A., Moore, I. D., . . . Zadvornaya, A. (2023). β− decay Q-value measurement of 136Cs and its implications for neutrino studies. Physical Review C, 108, Article 045502. https://doi.org/10.1103/PhysRevC.108.045502

JYU authors or editors

Ge, Zhuang
Eronen, Tommi
De Oliveira Ramalho, Marlom
Kotila, Jenni
Suhonen, Jouni
Nesterenko, Dmitrii
Kankainen, Anu
Beliuskina, Olga
Hukkanen, Marjut
Jaries, Arthur
Jokinen, Ari
Moore, Iain
Pirinen, Pekka
Romero Fernández, Jorge
Stryjczyk, Marek
Virtanen, Ville
Zadvornaya, Alexandra

Publication details

All authors or editors: Ge, Z.; Eronen, T.; de Roubin, A.; Ramalho, M.; Kostensalo, J.; Kotila, J.; Suhonen, J.; Nesterenko, D. A.; Kankainen, A.; Ascher, P.; et al.

Journal or series: Physical Review C

ISSN: 2469-9985

eISSN: 2469-9993

Publication year: 2023

Publication date: 11/10/2023

Volume: 108

Article number: 045502

Publisher: American Physical Society (APS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevC.108.045502

Publication open access: Not open

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/90615

Web address of parallel published publication (pre-print): https://arxiv.org/abs/2306.04604#

Abstract

The β− decay Q value of 136Cs (Jπ = 5+, t1/2 ≈ 13 d) was measured with the JYFLTRAP Penning trap setup at the Ion Guide Isotope Separator On-Line facility of the University of Jyväskylä, Finland. The monoisotopic samples required in the measurements were prepared with a new scheme utilized for the cleaning, based on the coupling of dipolar excitation with Ramsey’s method of time-separated oscillatory fields and the phase-imaging ion-cyclotron-resonance technique. The Q value is determined to be 2536.83(45) keV, which is ≈4 times more precise and 11.4(20) keV (≈6σ) smaller than the adopted value in the most recent Atomic Mass Evaluation AME2020. The daughter, 136Ba, has a 4+ state at 2544.481(24) keV and a 3− state at 2532.653(23) keV, both of which can potentially be ultralow Q-value end states for the 136Cs decay. With our new ground-to-ground state Q value, the decay energies to these two states become −7.65(45) keV and 4.18(45) keV, respectively. The former is confirmed to be negative at the level of ≈17σ, which verifies that this transition is not a suitable candidate for neutrino mass determination. On the other hand, the slightly negative Q value makes this transition an interesting candidate for the study of virtual β-γ transitions. The decay to the 3− state is validated to have a positive low Q value which makes it a viable candidate for neutrino mass determination. For this transition, we obtained a shell-model-based half-life estimate of 2.1+1.6 −0.8 × 1012 yr. Furthermore, the newly determined low reaction threshold of 79.08(54) keV for the charged-current νe + 136Xe (0+) → 136Cs∗ + e− neutrino capture process is used to update the cross sections for a set of neutrino energies relevant to solar 7 Be, pep, and CNO neutrinos. Based on our shell-model calculations, the new lower threshold shows event rates of 2–4 percent higher than the old threshold for several final states reached by the different species of solar neutrinos.

Keywords: nuclear physics

Fields of science: