Results Of A Search For Neutrinoless Double-Beta Decay Using The Cobra Demonstrator

Neutrinoless double-beta decay (0 nu beta beta decay) is a hypothetical process that can occur if the neutrino is its own antiparticle. The COBRA Collaboration operates a demonstrator to search for these decays at the Laboratori Nazionali del Gran Sasso in Italy using CdZnTe semiconductor detectors. The exposure of 234.7 kg d considered in this analysis was collected between September 2011 and February 2015. The analysis focuses on the decay of the nuclides Cd-114, Te-128, Zn-70, Te-130, and Cd-116. A Bayesian analysis is performed to estimate the signal strength of 0 nu beta beta decay. No signal is observed for any of these nuclides. Therefore, the following half-life limits at 90% credibility are set: T-1/2(0 nu) > 1.6x10(21) yr (Cd-114), T-1/2(0 nu) > 1.9x10(21) yr (Te-128), T-1/2(0 nu) > 6.8x10(18) yr (Zn-70), T-1/2(0 nu) > 6.1x10(21) yr (Te-130), and T-1/2(0 nu) > 1.1x10(21) yr (Cd-116).