2025/03/28 by Fan, Yingjie, Liu, Xuewen, Zhou, Ning
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2503.22155
The neutrino floor, a theoretical sensitivity limit for dark matter (DM) direct detections, is being redefined as the boundary of a dynamic ``neutrino fog", where neutrino signals become inevitable, obscuring DM detection due to the statistical and systematic uncertainties. This study provides the first site-specific analysis of the neutrino floor at China Jinping Underground Laboratory (CJPL), leveraging its unique geographic and environmental characteristics. We quantify how CJPL's suppressed atmospheric neutrino flux (around 30% lower than Laboratori Nazionali del Gran Sasso (LNGS)) reshapes the neutrino floor, thereby enabling improved sensitivity to high-mass WIMPs (mass >10 \rm GeV). Using a gradient-based framework, we derive CJPL's neutrino floor and estimate the detection prospects for the PandaX-xT experiment. Our results demonstrate that a 500 tonne-year exposure with PandaX-xT could touch the floor, probing spin independent cross-section down to σn∼ 3× 10-49 \rm cm2 at a DM mass of 70 GeV/c2.