First Measurements of Neutrino-Induced Nuclear Recoils Open New Avenues in Dark Matter and Neutrino Research

Recent measurements from the PandaX-4T and XENONnT experiments have reported the first observations of nuclear recoils induced by the $^8$B solar neutrino flux through the coherent elastic neutrino-nucleus scattering (CE$

u$NS) channel. This significant advancement marks a pivotal moment in both dark matter research and neutrino physics. The findings indicate that these detectors have achieved exposures that necessitate a new approach for analyzing low mass dark matter, specifically those under 10 GeV, as the traditional background-free paradigm is no longer applicable.

The implications of these measurements extend beyond dark matter searches. They signal the potential for these detectors to function as neutrino observatories, enhancing our understanding of neutrino interactions. The authors of the study, D. Aristizabal Sierra, N. Mishra, and L. Strigari, emphasize that despite the moderate statistical significance of the signals, the data already provide valuable insights into neutrino non-standard interactions (NSI).

The study reveals that the limits on NSI derived from the PandaX-4T and XENONnT measurements are comparable to those obtained from combined COHERENT CsI and LAr data, as well as the latest Ge measurement. Moreover, these findings offer sensitivity to pure $ au$ flavor parameters that are not accessible through other sources, such as stopped-pion or reactor sources. As statistical uncertainties improve and larger exposures are achieved, future data from these experiments are expected to yield important results related to CE$

u$NS physics.

This research is crucial for advancing our knowledge of both dark matter and neutrino physics, providing a foundation for future studies and potential discoveries in these fields. The full paper can be accessed at arXiv:2409.02003.