近日，华中师范大学的张冬亮&汪虎林及其研究团队取得一项新进展。经过不懈努力，他们对高压气体82SeF6 TPC中微子双β衰变实验中的太阳中微子背景进行研究。相关研究成果已于2024年4月15日在国际知名学术期刊《中国物理C》上发表。

在这项研究中，该研究团队探讨了在未来采用高压气体⁸²SeF₆ TPC进行无中微子双β衰变实验时，观测太阳中微子背景的可能性。研究人员模拟了各类贡献，并深入探讨了可用于事件分类的潜在特征，进而确定了两种主要的背景类型。

研究发现在30 keV ROI窗口中，多活背景事件的发生频率约为0.63事件/(吨·年)。然而，通过巧妙地应用基于集群数量和主要集群能量的筛选方法，该背景可以被有效地降低到小于0.0001事件/(吨·年)(95%置信水平)，同时仍能保持高达93%的信号效率。。

在ROI内，单电子背景事件的发生频率约为0.01事件/(吨·年)。若能成功研发出放射性背景抑制算法，并使其将单电子背景事件减少10倍，那么太阳中微子造成的总背景将降至0.001事件/(吨·年)。对于吨级实验而言，这一背景水平已足够低，足以满足实验需求。

附：英文原文

Title: Solar neutrino background in high-pressure gaseous ⁸²SeF₆ TPC neutrinoless double beta decay experiments

Author: Jiemiao Wang, Hulin Wang, Dongliang Zhang

Issue&Volume: 2024-04-15

Abstract: In this study, the possibility of observing a solar neutrino background in a future neutrinoless double beta decay experiment using a high-pressure gaseous ⁸²SeF₆ TPC is investigated. Various contributions are simulated, and possible features that could be used for event classification are discussed; two types of backgrounds are identified. The rate of multi-site background events is approximately 0.63 events/(ton·yr) in a 30 keV ROI window. This background could be effectively reduced to less than 0.0001 events/(ton·yr) (95% C.L.) while maintaining a high signal efficiency of 93% by applying a selection based on the number of clusters and energy of the leading cluster. The rate of the single-electron background events is approximately 0.01 events/(ton·yr) in the ROI. Assuming a reduction factor of 10 for the single-electron background events obtained via the algorithms developed for radioactive background rejection, the total background induced by the solar neutrino would be 0.001 events/(ton·yr), which is sufficiently small for conducting ton-level experiments.

DOI: 10.1088/1674-1137/ad2675

Source: http://hepnp.ihep.ac.cn/article/doi/10.1088/1674-1137/ad2675