Position reconstruction and surface background model for the PandaX-4T detector

• DOI: 10.48550/arxiv.2502.07317
• Publication Date: 2025-02-11
• Authors: Zhicheng Qian; Linhui Gu; Cheng Chen; Zihao Bo; Wei Chen; Xun Chen; Yunhua Chen; Zhaokan Cheng; Xiangyi Cui; Yingjie Fan; Deqing Fang; Zhixing Gao; Li-Sheng Geng; Karl Giboni; Xunan Guo; Xuyuan Guo; Zichao Guo; Chencheng Han; Han Ke; Changda He; Jinrong He; Di Huang; Houqi Huang; J. Huang; Ruquan Hou; Yu Hou; Xiangdong Ji; X. Ji; Yonglin Ju; Chenxiang Li; Jiafu Li; Mingchuan Li; Shuaijie Li; Tao Li; Zhiyuan Li; Qing Lin; Jianglai Liu; Congcong Lu; Xiaoying Lu; Lingyin Luo; Yunyang Luo; Wenbo Ma; Yugang Ma; Yajun Mao; Meng Yue; Xuyang Ning; Binyu Pang; Ningchun Qi; Xiangxiang Ren; Dong Shan; Xiaofeng Shang; Xiyuan Shao; Guofang Shen; Manbin Shen; Wenliang Sun; Tao Yi; Anqing Wang; Guanbo Wang; Hao Wang; Jiamin Wang; Yaohui Wang; Meng Wang; Qiu-Hong Wang; Shaobo Wang; Siguang Wang; Wei Wang; Xiuli Wang; Xu Wang; Weijia Zhou; Yuehuan Wei; Weihao Wu; Yuan Wu; Mengjiao Xiao; Xiang Xiao; Kaizhi Xiong; Yifan Xu; Shunyu Yao; Binbin Yan; Xiyu Yan; Yong Yang; Peihua Ye; Chunxu Yu; Ying Yuan; Zhe Yuan; Youhui Yun; Xinning Zeng; Minzhen Zhang; Peng Zhang; Shibo Zhang; Shu Zhang; Tao Zhang; Wei Zhang; Yang Zhang; Yingxin Zhang; Yuanyuan Zhang; Zhao Li; Jifang Zhou; Jiaxu Zhou; Jiayi Zhou; N. Zhou; Xiaopeng Zhou; Yubo Zhou; Zhizhen Zhou
• Keywords: Position (finance)

We report the position reconstruction methods and surface background model for PandaX-4T dark matter direct search experiment. This work develops two algorithms: template matching (TM) method photon acceptance function (PAF) method. Both determine horizontal of events based on light pattern secondary scintillation collected by sensors. After a comprehensive evaluation resolution, uniformity, robustness, PAF was selected reconstruction, while TM employed verification. The achieves bulk event resolution 1.0 mm 4.4 typical $S2$ signal with bottom charge 1500 PE (about 14 keV). uniformity is around 20\%. Robustness studies reveal average deviations 5.1 8.8 commissioning run (Run0) first science (Run1), respectively, due to deactivation certain PMTs. A data-driven developed estimated be $0.09 \pm 0.06$ Run0 (0.54 tonne$\cdot$year) $0.17 0.11$ Run1 (1.00 tonne$\cdot$year).