Results on neutrinoless double beta decay of 76Ge from GERDA Phase i

Abstract

The Germanium Detector Array (GERDA) experiment is searching for the neutrinoless double beta (0νββ) decay of 76Ge by operating bare germanium diodes in liquid argon. GERDA is located at the Gran Sasso National Laboratory (LNGS) in Italy. During Phase I, a total exposure of 21.6 kg yrand a background index of 0.01 cts/(keVkg yr) were reached. No signal was observed and a lower limit of T0ν1/2 > 2.1 • 1025 yr(90% C.L.) is derived for the half life of the 0νββ decay of 76Ge.