# The first result on 76Ge neutrinoless double beta decay from CDEX-1 experiment **Authors:** Li Wang, Qian Yue, KeJun Kang, JianPing Cheng, YuanJing Li, TszKing, Henry Wong, ShinTed Lin, JianPing Chang, JingHan Chen, QingHao Chen, YunHua, Chen, Zhi Deng, Qiang Du, Hui Gong, Li He, QingJu He, JinWei Hu, HanXiong, Huang, TengRui Huang, LiPing Jia, Hao Jiang, HauBin Li, Hong Li, JianMin Li,, Jin Li, Jun Li, Xia Li, XinYing Li, XueQian Li, YuLan Li, FongKay Lin, ShuKui, Liu, Hao Ma, JingLu Ma, XingYu Pan, Jie Ren, XiChao Ruan, ManBin Shen, Vivek, Sharma, Lakhwinder Singh, Manoj Kumar Singh, Manoj Kumar Singh, Arun Kumar, Soma, Jian Su, ChangJian Tang, WeiYou Tang, ChaoHsiung Tseng, JiMin Wang,, Qing Wang, ShiYong Wu, Wei Wu, YuCheng Wu, HaoYang Xing, Yin Xu, Tao Xue,, LiTao Yang, SongWei Yang, Nan Yi, ChunXu Yu, HaiJun Yu, WeiHe Zeng, XiongHui, Zeng, Zhi Zeng, Lan Zhang, YunHua Zhang, MingGang Zhao, Wei Zhao, SuNing, Zhong, JiFang Zhou, ZuYing Zhou, JingJun Zhu, WeiBin Zhu, and ZhongHua Zhu arXiv: 1703.01877 · 2018-02-28 ## TL;DR This paper reports the first experimental search for neutrinoless double beta decay in Ge-76 using the CDEX-1 detector, setting new limits on decay half-life and neutrino mass. ## Contribution It presents the first results from the CDEX-1 experiment on Ge-76 neutrinoless double beta decay, including new half-life limits and background analysis methods. ## Key findings - Half-life > 6.4×10^22 years at 90% CL - Effective Majorana neutrino mass limit of 5.0 eV - Background reduction strategies discussed ## Abstract We report the first result on Ge-76 neutrinoless double beta decay from CDEX-1 experiment at China Jinping Underground Laboratory. A mass of 994 g p-type point-contact high purity germanium detector has been installed to search the neutrinoless double beta decay events, as well as to directly detect dark matter particles. An exposure of 304 kg*day has been analyzed. The wideband spectrum from 500 keV to 3 MeV was obtained and the average event rate at the 2.039 MeV energy range is about 0.012 count per keV per kg per day. The half-life of Ge-76 neutrinoless double beta decay has been derived based on this result as: T 1/2 > 6.4*10^22 yr (90% C.L.). An upper limit on the effective Majorana-neutrino mass of 5.0 eV has been achieved. The possible methods to further decrease the background level have been discussed and will be pursued in the next stage of CDEX experiment. --- Source: https://tomesphere.com/paper/1703.01877