Powered by Indico
v3.2.3
Abstract:XENONnT is a dual-phase liquid xenon time projection chamber operating at LNGS with a 5.9-tonne active target, designed to search for weakly interacting massive particles (WIMPs). As its sensitivity reaches the irreducible background from solar neutrino coherent scattering, the experiment enters a new regime — the "neutrino fog" — where neutrino and dark matter signals become increasingly difficult to disentangle.
We report a 3.3σ measurement of coherent elastic neutrino-nucleus scattering (CEνNS) from solar ⁸B neutrinos using a combined exposure of 6.77 t×yr across three science runs. The inferred ⁸B flux of (5−2+3)×10⁶ cm⁻²s⁻¹ is consistent with the Standard Solar Model. In the presence of this neutrino fog, a search for light dark matter finds no signal excess, and a near-doubling of exposure improves the median sensitivity to 5 GeV/c² WIMPs by only ~10%, providing a direct experimental demonstration of diminishing returns.
The dataset is further used to measure the weak mixing angle sin2θW at ~0.02 GeV/c momentum transfer and to constrain new vector mediators and the neutrino magnetic moment, highlighting the versatility of the liquid xenon TPC as a precision probe of both neutrino physics and physics beyond the Standard Model.
Biography:Kexin Liu is a PhD candidate in the Department of Physics at Tsinghua University, supported by the Tsinghua University "Future Scholar" Fellowship. She is a member of the XENON Collaboration and former subgroup leader of the "Signal and Detector Physics" analysis group. She served as one of the lead analysts for the solar ⁸B neutrino signal physics analysis in XENONnT, responsible for the suppression, modeling, and validation of the dominant accidental coincidence background, and is a corresponding author of the publication. Her work on solar neutrino physics analysis was recognized with the National Scholarship for Graduate Students, the Best Oral Presentation Award in the Direct Detection Experimental category at IDM 2024, and the Chien-Shiung Wu Diploma at ISSP 2025.
Alternatively online link:https://meeting.tencent.com/dm/ydFjmub7SnMo
ID：838-498-931