e-Article
Searching for $^{76}$Ge neutrinoless double beta decay with the CDEX-1B experiment
Document Type
Working Paper
Author
Zhang, B. T.; Wang, J. Z.; Yang, L. T.; Yue, Q.; Kang, K. J.; Li, Y. J.; An, H. P.; C., Greeshma; Chang, J. P.; Chen, Y. H.; Cheng, J. P.; Dai, W. H.; Deng, Z.; Fang, C. H.; Geng, X. P.; Gong, H.; Guo, Q. J.; Guo, X. Y.; He, L.; He, S. M.; Hu, J. W.; Huang, H. X.; Huang, T. C.; Jia, H. T.; Jiang, X.; Karmakar, S.; Li, H. B.; Li, J. M.; Li, J.; Li, Q. Y.; Li, R. M. J.; Li, X. Q.; Li, Y. L.; Liang, Y. F.; Liao, B.; Lin, F. K.; Lin, S. T.; Liu, J. X.; Liu, S. K.; Liu, Y. D.; Liu, Y.; Liu, Y. Y.; Liu, Z. Z.; Ma, H.; Mao, Y. C.; Nie, Q. Y.; Ning, J. H.; Pan, H.; Qi, N. C.; Ren, J.; Ruan, X. C.; She, Z.; Singh, M. K.; Sun, T. X.; Tang, C. J.; Tang, W. Y.; Tian, Y.; Wang, G. F.; Wang, L.; Wang, Q.; Wang, Y. F.; Wang, Y. X.; Wong, H. T.; Wu, S. Y.; Wu, Y. C.; Xing, H. Y.; Xu, R.; Xu, Y.; Xue, T.; Yan, Y. L.; Yi, N.; Yu, C. X.; Yu, H. J.; Yue, J. F.; Zeng, M.; Zeng, Z.; Zhang, F. S.; Zhang, L.; Zhang, Z. H.; Zhang, Z. Y.; Zhao, K. K.; Zhao, M. G.; Zhou, J. F.; Zhou, Z. Y.; Zhu, J. J.
Source
Chin. Phys. C 48, 101001 (2024)
Subject
Language
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 ($0\nu\beta\beta$) decay of $^{76}$Ge. A total of 504.3 kg$\cdot$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$-$2089 keV for this work) with a factor of 23. A background level of 0.33 counts/(keV$\cdot$kg$\cdot$yr) was realized. The lower limit on the half life of $^{76}$Ge $0\nu\beta\beta$ decay was constrained as $T_{1/2}^{0\nu}\ > \ {1.0}\times 10^{23}\ \rm yr\ (90\% \ C.L.)$, corresponding to the upper limits on the effective Majorana neutrino mass: $\langle m_{\beta\beta}\rangle < $3.2$-$7.5$\ \mathrm{eV}$.
Comment: 11 pages, 12 figures, 2 tables. Version updated to match CPC version
Comment: 11 pages, 12 figures, 2 tables. Version updated to match CPC version