Searching for 76 Ge neutrinoless double beta decay with the CDEX-1B experiment

• Published in: Chinese physics C Vol. 48; no. 10; p. 103001
• Main Authors: Zhang 张, Bing-Tao 炳韬, Wang 王, Jun-Zheng 军正, Yang 杨, Li-Tao 丽桃, Yue 岳, Qian 骞, Kang 康, Ke-Jun 克军, Li 李, Yuan-Jing 元景, An 安, Hai-Peng 海鹏, Greeshma, C., Chang 常, Jian-Ping 建平, Chen 陈, Yun-Huan 云华, Cheng 程, Jian-Ping 建平, Dai 代, Wen-Han 文翰, Deng 邓, Zhi 智, Fang 房, Chang-Hao 昌昊, Geng 耿, Xin-Ping 新平, Gong 宫, Hui 辉, Guo 郭, Qiu-Ju 秋菊, Guo 郭, Xu-Yuan 绪元, He 何, Li 力, He 何, Sheng-Ming 胜明, Hu 胡, Jin-Wei 津纬, Huang 黄, Han-Xiong 翰雄, Huang 黄, Tu-Chen 土琛, Jia 贾, Hai-Tao 海涛, Jiang 蒋, Xi 熙, Karmakar, S., Li 李, Hao-Bin 浩斌, Li 李, Jian-Min 荐民, Li 李, Jin 金, Li 李, Qian-Yun 倩沄, Li 李, Ren-Ming-Jie 任明杰, Li 李, Xue-Qian 学潜, Li 李, Yu-Lan 玉兰, Liang 梁, Yi-Fan 艺帆, Liao 廖, Bin 斌, Lin 林, Fong-Kay 枫凯, Lin 林, Shin-Ted 兴德, Liu 刘, Jia-Xuan 家璇, Liu 刘, Shu-Kui 书魁, Liu 刘, Yan-Dong 言东, Liu 刘, Yu 钰, Liu 刘, Yuan-Yuan 圆圆, Liu 刘, Zhong-Zhi 仲智, Ma 马, Hao 豪, Mao 茅, Yu-Cai 钰才, Nie 聂, Qi-Yuan 奇缘, Ning 宁, Jin-Hua 金华, Pan 潘, Hui 辉, Qi 祁, Ning-Chun 宁春, Ren 任, Jie 杰, Ruan 阮, Xi-Chao 锡超, She 佘, Ze 泽, Singh, Manoj Kumar, Sun 孙, Tian-Xi 天希, Tang 唐, Chang-Jian 昌建, Tang 唐, Wei-You 维优, Tian 田, Yang 阳, Wang 王, Guang-Fu 广甫, Wang 王, Li 力, Wang 王, Qing 青, Wang 王, Yu-Feng 钰锋, Wang 王, Yun-Xiang 云祥, Wong 王, Henry-Tsz-King 子敬, Wu 吴, Shi-Yong 世勇, Wu 吴, Yu-Cheng 玉成, Xing 幸, Hao-Yang 浩洋, Xu 徐, Rui 锐, Xu 徐, Yin 音, Xue 薛, Tao 涛, Yan 鄢, Yu-Lu 雨璐, Yi 易, Nan 难, Yu 喻, Chun-Xu 纯旭, Yu 于, Hai-Jun 海军, Yue 岳, Jian-Feng 剑锋, Zeng 曾, Ming 鸣, Zeng 曾, Zhi 志, Zhang 张, Feng-Shou 丰收, Zhang 张, Lei 磊, Zhang 张, Zhen-Hua 振华, Zhang 张, Zhen-Yu 震宇, Zhao 赵, Kang-Kang 康康, Zhao 赵, Ming-Gang 明刚, Zhou 周, Ji-Fang 济芳, Zhou 周, Zu-Ying 祖英, Zhou 朱, Jing-Jun 敬军, （CDEX Collaboration）
• Format: Journal Article
• Language: English
• Published: 01.10.2024
• ISSN: 1674-1137; 2058-6132
• DOI: 10.1088/1674-1137/ad597b

Abstract We operated a p -type point contact high purity germanium (PPCGe) detector (CDEX-1B, 1.008 kg) in the China Jinping Underground Laboratory (CJPL) for 500.3 days to search for neutrinoless double beta ( ) decay of 76 Ge. A total of 504.3 kg day effective exposure data was accumulated. The anti-coincidence and the multi/single-site event (MSE/SSE) discrimination methods were used to suppress the background in the energy region of interest (ROI, 1989–2089 keV for this work) with a factor of 23. A background level of 0.33 counts/ (keV kg yr) was realized. The lower limit on the half life of 76 Ge decay was constrained as , corresponding to the upper limits on the effective Majorana neutrino mass: 3.2–7.5 .