First results on 76Ge neutrinoless double beta decay from CDEX-1 experiment

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2017,（7）
• 页码范围: 53-59
• 页数: 7页
• 语种: 英文
• DOI: 10.1007/s11433-017-9038-4

摘要

We report the first results on 76Ge neutrinoless double beta decay from stage one of the China dark-matter experiment (CDEX).A p-type point-contact high-purity germanium detector with a mass of 994g has been installed to detect neutrinoless double beta decay events,as well as to directly detect dark matter particles.An exposure of 304kgd has been analyzed over a wide spectral band from 500 keV to 3 MeV.The average event rate obtained was about 0.012 counts per keV per kg per day over the 2.039 MeV energy range.The half-life of 76Ge neutrinoless double beta decay derived based on this result is T0v/2＞6.4× 1022 yr (90％C.L.).An upper limit on the effective Majorana-neutrino mass of 5.0eV has been achieved.