XENON Collaboration2021-04-212021-04-212021XENON Collaboration. "Search for Coherent Elastic Scattering of Solar 8B Neutrinos in the XENON1T Dark Matter Experiment." <i>Physical Review Letters,</i> 126, no. 9 (2021) American Physical Society: https://doi.org/10.1103/PhysRevLett.126.091301.https://hdl.handle.net/1911/110295We report on a search for nuclear recoil signals from solar 8B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 to 1.6 keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant 8B neutrinolike excess is found in an exposure of 0.6 t×y. For the first time, we use the nondetection of solar neutrinos to constrain the light yield from 1–2 keV nuclear recoils in liquid xenon, as well as nonstandard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 and 11 GeV c−2 by as much as an order of magnitude.engPublished by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Journal articlePhysRevLett-126-091301https://doi.org/10.1103/PhysRevLett.126.091301