Abstract
Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of $^{36}$Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of $^{36}$Ar was established: $T_{1/2} > $ 3.6 $\times$ 10$^{21}$ yr at 90 % C.I.
Highlights
The observation of neutrinoless double beta decay (0νββ):(A, Z − 2) → (A, Z) + 2e−, (1)can provide unambiguous information on lepton number violation and indicate the Majorana nature of neutrinos, regardless the physics mechanism responsible for the decay
Many experiments are searching for this decay considering different isotopes. Among these there is the Gerda (GERmanium Detector Array) experiment [1] implementing bare germanium detectors enriched in 76Ge
Another lepton number violating process that can provide the same information as neutrinoless double beta decay is the double capture of two bound atomic electrons without the emission of neutrinos (0νECEC): 2e− + (A, Z + 2) → (A, Z) + Q, (2)
Summary
The observation of neutrinoless double beta decay (0νββ):. can provide unambiguous information on lepton number violation and indicate the Majorana nature of neutrinos, regardless the physics mechanism responsible for the decay. The best limit on 0νββ decay halflife of 76Ge has been published by the Gerda collaboration [2] Another lepton number violating process that can provide the same information as neutrinoless double beta decay is the double capture of two bound atomic electrons without the emission of neutrinos (0νECEC): 2e− + (A, Z + 2) → (A, Z) + Q,. Geochemical measurement of 130Ba decay into 130Xe [8,9] and the second is a large-volume copper proportional counter searching for double K-shell capture in 78Kr [10] Several experiments including the latter established limits on both neutrino accompanied and neutrinoless double electron capture of different isotopes This paper reports the search for the 429.88 keV γ line from 0νECEC decay of 36Ar with Gerda Phase I germanium detectors and the determination of a limit on its half-life
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
