XENONnT detector records solar neutrinos at unprecedentedly low energies
Physicists using the XENONnT dark-matter experiment have identified solar neutrinos with energies as low as 17 keV, the lowest ever observed.
Researchers operating the XENONnT experiment in Italy have announced the first definitive detection of solar neutrinos with energies down to 17 keV, a tenth of the lowest energies previously recorded. By observing faint light produced when neutrinos collide with electrons inside the detector, the team identified hundreds of such events, achieving a 5-sigma statistical confidence. The finding, detailed in an arXiv-submitted manuscript, marks the first time a dark-matter detector has used electron-scattering signatures to confirm neutrinos.
A prior study by PandaX-4T in China reported a similar effect but only at about 2.2 sigma, insufficient for a firm claim. The low-energy neutrinos arise from the Sun’s dominant proton-proton fusion chain, and future, more sensitive detectors could exploit them to probe the Sun’s interior composition.
Why it matters
Detecting ultra-low-energy solar neutrinos opens a new method for studying the Sun’s core and testing particle-physics models.
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