XENONnT detects lowest-energy solar neutrinos yet, down to 17 keV
The XENONnT dark matter detector has captured solar neutrinos at energies as low as 17 keV, far below the previous 200 keV threshold, showing its low-background sensitivity.
The story in focus
The XENONnT experiment, designed to search for dark matter, has detected solar neutrinos at energies down to 17 keV—far lower than the previous 200 keV threshold. The collaboration says the result demonstrates the detector's ultra-low background and opens new neutrino studies.
- XENONnT captured solar neutrinos with energies as low as 17 keV, compared with about 200 keV in earlier experiments.
- The detector, filled with six tons of pure xenon and buried 4,600 feet under Gran Sasso mountain, was built to suppress background noise.
- The data came from only the first phase of XENONnT; the detector has since been upgraded and further data are expected.
A dark matter detector turns to neutrinos
The XENONnT experiment was designed to search for dark matter, but its sensitivity allowed it to capture a different target: solar neutrinos. The detector sits 4,600 feet deep in Italy's Gran Sasso mountain, which shields it from cosmic rays. It contains six tons of pure xenon; if a neutrino or dark matter particle strikes a xenon atom, the detector records the collision. Ultra-pure materials reduce background noise.
According to the University of Chicago, the collaboration measured solar neutrinos through elastic neutrino-electron scattering at energies down to 17 keV. Earlier experiments could only detect solar neutrinos at around 200 keV.
What the measurement shows
Luca Grandi, a University of Chicago physicist who led the design and construction of XENONnT, said the low background makes the experiment an observatory for rare processes. The result adds sensitivity to neutrino physics, he said, even though XENON is smaller than most dedicated neutrino experiments.
The analyzed data came from only the first phase of XENONnT. The detector has since been upgraded, and forthcoming data should provide a further window on the results, Grandi noted.
What energy range did XENONnT reach for solar neutrinos?
XENONnT detected solar neutrinos at energies down to 17 keV, compared with about 200 keV for earlier experiments, according to the University of Chicago.
Sources & further reading
- XENON experiment finds quietest neutrinos ever detected ↗news.uchicago.edu
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