Measurement of the Spectral Shape of the $$β$$-Decay of ¹³⁷Xe to the Ground State of ¹³⁷Cs in EXO-200 and Comparison with Theory

Journal Article · Fri Jun 12 00:00:00 EDT 2020 · Physical Review Letters

DOI:https://doi.org/10.1103/physrevlett.124.232502· OSTI ID:1637701

Al Kharusi, S.; Anton, G.; Badhrees, I.; Barbeau, P. S.; Beck, D.; Belov, V.; Bhatta, T.; Breidenbach, M.; Brunner, T.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Daniels, T.; Darroch, L.; Daugherty, S. J.; Davis, J.; Delaquis, S. ; Der Mesrobian-Kabakian, A.; DeVoe, R.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Echevers, J.; Fairbank, W.; Fairbank, D.; Farine, J.; Feyzbakhsh, S.; Fierlinger, P.; Fudenberg, D.; Gautam, P.; Gornea, R.; Gratta, G.; Hall, C.; Hansen, E. V.; Hoessl, J.; Hufschmidt, P.; Hughes, M.; Iverson, A.; Jamil, A.; Jessiman, C.; Jewell, M. J.; Johnson, A.; Karelin, A.; Kaufman, L. J.; Koffas, T.; Kostensalo, J.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Lan, Y.; Larson, A.; Lenardo, B. G.; Leonard, D. S.; Li, G. S.; Li, S.; Li, Z.; Licciardi, C.; Lin, Y. H.; MacLellan, R.; McElroy, T.; Michel, T.; Mong, B.; Moore, D. C.; Murray, K.; Nakarmi, P.; Njoya, O.; Nusair, O.; Odian, A.; Ostrovskiy, I. ; Piepke, A.; Pocar, A.; Retière, F.; Robinson, A. L.; Rowson, P. C.; Ruddell, D.; Runge, J.; Schmidt, S.; Sinclair, D.; Skarpaas, K.; Soma, A. K.; Stekhanov, V.; Suhonen, J.; Tarka, M.; Thibado, S.; Todd, J.; Tolba, T.; Totev, T. I.; Tsang, R.; Veenstra, B.; Veeraraghavan, V.; Vogel, P.; Vuilleumier, J. -L.; Wagenpfeil, M.; Watkins, J.; Weber, M.; Wen, L. J.; Wichoski, U.; Wrede, G.; Wu, S. X.; Xia, Q.; Yahne, D. R.; Yang, L.; Yen, Y. -R.; Zeldovich, O. Ya.; Ziegler, T.

We report on a comparison between the theoretically predicted and experimentally measured spectra of the first-forbidden nonunique β-decay transition 137Xe(7/2-) → 137Cs(7/2+). The experimental data were acquired by the EXO-200 experiment during a deployment of an AmBe neutron source. The ultralow background environment of EXO-200, together with dedicated source deployment and analysis procedures, allowed for collection of a pure sample of the decays, with an estimated signal to background ratio of more than 99 to 1 in the energy range from 1075 to 4175 keV. In addition to providing a rare and accurate measurement of the first-forbidden nonunique β decay shape, this work constitutes a novel test of the calculated electron spectral shapes in the context of the reactor antineutrino anomaly and spectral bump.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States); Univ. of Alabama, Tuscaloosa, AL (United States)
• Sponsoring Organization: National Science Foundation (NSF); Natural Sciences and Engineering Research Council of Canada (NSERC); Institute for Basic Science (IBS); Russian Foundation for Basic Research (RFBR); German Research Foundation (DFG); Chinese Academy of Sciences (CAS); International Science and Technology Cooperation Program of China (ISTCP); Academy of Finland; Jenny and Antti Wihuri Foundation; USDOE Office of Nuclear Energy (NE)
• Contributing Organization: EXO-200 Collaboration
• Grant/Contract Number: AC02-76SF00515; SC0017970; FG02-01ER41166
• OSTI ID: 1637701
• Alternate ID(s): OSTI ID: 1660469; OSTI ID: 1830732
• Journal Information: Physical Review Letters, Vol. 124, Issue 23; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Beta decay
Nuclear many-body theory
Nuclear structure & decays
90 ≤ A ≤ 149