The GERDA experiment: results and perspectives

11th International Conference on Hyperons, Charm and Beauty Hadrons

Macolino, Carla^1,2,2

INFN, Laboratori Nazionali Del Gran Sasso, L'Aquila, Italy^1

INFN, Gran Sasso Science Institute, L'Aquila, Italy^2

关键词: Background level;    Germanium detector;    Half lives;    In-phase;    Liquid argon;    Majorana neutrino;    Model independent;    Pulse shape analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/556/1/012063/pdf
DOI  :  10.1088/1742-6596/556/1/012063

来源: IOP

【 摘 要 】

The Germanium Detector Array, GERDA, at Laboratori Nazionali del Gran Sasso (Italy), is designed to search for Majorana neutrinos via neutrinoless double beta (0νββ) decay of76Ge. GERDA completed the Phase I in 2013, after an exposure of 21.6 kg·yr and with a background of about 0.01 cts/(keVkgyr): no signal was found and a limit on the half-life of T0ν1/2> 2.1 · 1025yr (90% C.L.) was established. The previous claim of 0νββ observation for76Ge is strongly disfavoured in a model independent way. The commission for GERDA Phase II is currently ongoing and about 20 kg of additional enriched Ge diodes will be deployed. Pulse- shape analysis, together with the liquid argon instrumentation will allow to reach a background level one order of magnitude lower than in Phase I. In this paper the measurement of the half-life of 0νββ decay from GERDA Phase I and the expected sensitivity for Phase II are discussed.