Probing the Solar ⁸B Neutrino Fog with XENONnT

We report a 3.3 $σ$ measurement of coherent elastic neutrino-nucleus scattering from solar ⁸B neutrinos using a 6.77 t×yr exposure from the XENONnT experiment, inferring a solar ⁸B neutrino flux of (5₋₂⁺³)× 10⁶\,cm⁻²s⁻¹, consistent with previous measurements. In the presence of the ⁸B "neutrino fog", we find no evidence for light dark matter, and observe diminishing returns in sensitivity with increasing exposure. A 93% increase in exposure from the previous search improves the median sensitivity to the nucleon scattering cross section for a 5 GeV/c² spin-independent weakly interacting massive particle by 10%. The dataset was also used to measure the weak mixing angle at ~ 0.02 GeV/c momentum transfer and constrain physics beyond the Standard Model.