Searches for neutrinoless resonant double electron captures at LNGS

TL;DR

This paper reports on underground experiments at LNGS searching for neutrinoless resonant double electron captures in various isotopes, setting new half-life limits but finding no evidence of such decays.

Contribution

First experimental search for neutrinoless resonant double electron captures at LNGS using multiple detectors, establishing new half-life limits for several isotopes.

Findings

No evidence of neutrinoless resonant double electron captures was observed.

Half-life limits established in the range of 10^{14} to 10^{21} years.

Experimental constraints improve previous bounds on these rare decay processes.

Abstract

Several experiments were performed during last years at underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (LNGS) of the INFN (Italy) to search for resonant 2$\varepsilon0\nu$ captures in 96Ru, 106Cd, 136Ce, 156Dy, 158Dy, 180W, 184Os, 190Pt with the help of HP Ge semiconductor detectors, and ZnWO4 and 106CdWO4 crystal scintillators. No evidence for r-2$\varepsilon0\nu$ decays was found, and only T_{1/2} limits were established in the range of 10^{14}-10^{21} yr.