The China Jinping underground Laboratory (CJPL) is an excellent location for studying solar, terrestrial, and supernova neutrinos due to its 2400-meter vertical rock overburden. Its unparalleled depth gives an opportunity to investigate the cosmic-ray muons with exceptionally high average energy at ∼360 GeV. This paper details a study of muon-related backgrounds based on 1178 days of data collected by the 1-ton prototype neutrino detector used for the Jinping Neutrino Experiment (JNE) since 2017. The apparent effects for the leakage of muons' secondary particles due to detector's finite size on the measured neutron yield are first discussed in detail. The analysis of 493 cosmic-ray muon candidates and 13.6±5.7 cosmogenic neutron candidates, along with a thorough evaluation of detection efficiency and uncertainties, gives a muon flux of (3.56±0.16stat.±0.10syst.)×10−10cm−2s−1 and a cosmogenic neutron yield of (3.37±1.41stat.±0.31syst.)×10−4μ−1g−1cm2 in LAB-based liquid scintillator.
@article{arxiv.2409.04169,
title = {Study of neutron production for 360 GeV cosmic muons},
author = {Xinshun Zhang and Jinjing Li and Shaomin Chen and Wei Dou and Haoyang Fu and Ye Liang and Qian Liu and Wentai Luo and Ming Qi and Wenhui Shao and Haozhe Sun and Jian Tang and Yuyi Wang and Zhe Wang and Changxu Wei and Jun Weng and Yiyang Wu and Benda Xu and Chuang Xu and Tong Xu and Yuzi Yang and Aiqiang Zhang and Bin Zhang},
journal= {arXiv preprint arXiv:2409.04169},
year = {2025}
}