Электронный каталог

Статья

Agostini, M.
Search for the In-Situ Production of *7*7Ge in the GERDA Neutrinoless Double-Beta Experiment / M.Agostini, M.Fomina, K.Gusev, A.Klimenko, O.Kochetov, A.Lubashevskiy, I.Nemchenok, N.Rumyantseva, E.Shevchik, M.Shirchenko, A.Smolnikov, I.Zhitnikov, D.Zinatulina, [a.o.]. – Text : electronic // The European Physical Journal C. – 2025. – Vol. 85, No. 7. – P. 809. – URL: https://doi.org/10.1140/epjc/s10052-025-14445-x. – Bibliogr.: 17.

The beta decay of *7*7Ge and *7*7mGe, both produced by neutron capture on *7*6Ge, is a potential background for Germanium based neutrinoless double-beta decay search experiments such as GERDA or the LEGEND experiment. In this work we present a search for *7*7Ge decays in the full GERDA Phase II data set. A delayed coincidence method was employed to identify the decay of *7*7Ge via the isomeric state of *7*7As (9/2*+, 475 keV, T&sub(1/2) = 114µs, &sup(77m)As). New digital signal processing methods were employed to select and analyze pile-up signals. No signal was observed, and an upper limit on the production rate of *7*7Ge was set at < 0.216 nuc/(kg· yr) (90% CL). This corresponds to a total production rate of *7*7Ge and *7*7mGe of < 0.38 nuc/(kg· yr) (90% CL), assuming equal production rates. A previous Monte Carlo study predicted a value for in-situ *7*7Ge and *7*7mGe production of (0.21 ± 0.07) nuc/(kg.yr), a prediction that is now further corroborated by our experimental limit. Moreover, tagging the isomeric state of *7*7mAs can be utilised to further suppress the *7*7Ge background. Considering the similar experimental configurations of LEGEND-1000 and GERDA, the cosmogenic background in LEGEND-1000 at LNGS is estimated to remain at a sub-dominant level.



ОИЯИ = ОИЯИ (JINR)2025