Neutrino-less Double Beta Decay of 48Ca studied by CaF2(Eu) Scintillators

TL;DR

This study searches for neutrino-less double beta decay in 48Ca using CaF2(Eu) scintillators, setting new lower limits on the decay half-life with no observed events, thus constraining neutrino properties.

Contribution

First application of pulse shape analysis with CaF2(Eu) scintillators to search for 0νββ decay of 48Ca, establishing more stringent half-life limits.

Findings

No 0νββ events observed in the data.

Lower limit of half-life T > 5.8 x 10^22 years at 90% confidence.

Pulse shape analysis effectively reduces background.

Abstract

We searched for the neutrino-less double beta decay(0nbb) of 48Ca by using CaF2(Eu) scintillators. Analysis of their pulse shapes was effective to reduce backgrounds. No events are observed in the Q-value region for the data of 3394 kg days. It gives a lower limit (90% confidence level) of T > 2.7 x 10^22 year for the half life of 0nbb of 48Ca. Combined with our previous data for 1553 kg days, we obtained more stringent limit of T > 5.8 x 10^22 year.