First Directional Measurement of sub-MeV Solar Neutrinos with Borexino

Abstract

We report the measurement of sub-MeV solar neutrinos through the use of their associated Cherenkov radiation, performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The measurement is achieved using a novel technique that correlates individual photon hits of events to the known position of the Sun. In an energy window between 0.54 MeV to 0.74 MeV, selected using the dominant scintillation light, we have measured 10887${}_{-2103}^{+2386}(stat.)\pm 947(syst.)$ ($68\%$ confidence interval) solar neutrinos out of 19904 total events. This corresponds to a ${}^7$Be neutrino interaction rate of 51.6${}_{-12.5}^{+13.9}$ counts/(day$\cdot$ 100 ton), which is in agreement with the Standard Solar Model predictions and the previous spectroscopic results of Borexino. The no-neutrino hypothesis can be excluded with $>$5$\sigma$ confidence level. For the first time, we have demonstrated the possibility of utilizing the directional Cherenkov information for sub-MeV solar neutrinos, in a large-scale, high light yield liquid scintillator detector. This measurement provides an experimental proof of principle for future hybrid event reconstruction using both Cherenkov and scintillation signatures simultaneously.

arXiv comment6 pages, 4 figures, short letter of arXiv:2109.04770

References in corpus (37)

• Measurement of the rate of nu_e + d --> p + p + e^- interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory
• Neutrino Physics with JUNO
• Constraints on Neutrino Oscillations Using 1258 Days of Super-Kamiokande Solar Neutrino Data
• Measurement of the solar neutrino capture rate with gallium metal. III: Results for the 2002--2007 data-taking period
• Precision measurement of the 7Be solar neutrino interaction rate in Borexino
• The Borexino detector at the Laboratori Nazionali del Gran Sasso
• A new Generation of Standard Solar Models
• Solar Neutrino Measurements in Super-Kamiokande-IV
• Final results of Borexino Phase-I on low energy solar neutrino spectroscopy
• First evidence of pep solar neutrinos by direct detection in Borexino
• Low Energy Threshold Analysis of the Phase I and Phase II Data Sets of the Sudbury Neutrino Observatory
• Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun
• Solar neutrinos as probes of neutrino-matter interactions
• Limiting neutrino magnetic moments with Borexino Phase-II solar neutrino data
• Simultaneous Precision Spectroscopy of $pp$, ${}^7$Be, and $pep$ Solar Neutrinos with Borexino Phase-II
• Theia: An advanced optical neutrino detector
• Comprehensive geoneutrino analysis with Borexino
• Borexino calibrations: Hardware, Methods, and Results
• Atmospheric Neutrino Oscillation Analysis With Improved Event Reconstruction in Super-Kamiokande IV
• 7Be Solar Neutrino Measurement with KamLAND
• Measuring Directionality in Double-Beta Decay and Neutrino Interactions with Kiloton-Scale Scintillation Detectors
• Slow Liquid Scintillator Candidates for MeV-scale Neutrino Experiments
• Cherenkov and Scintillation Light Separation in Organic Liquid Scintillators
• Measurement of the ${}^8$B Solar Neutrino Flux in SNO+ with Very Low Backgrounds
• Development, characterisation, and deployment of the SNO+ liquid scintillator
• The Monte Carlo simulation of the Borexino detector
• Spectral Photon Sorting For Large-Scale Cherenkov and Scintillation Detectors
• MeV-scale performance of water-based and pure liquid scintillator detectors
• Cherenkov and Scintillation Light Separation Using Wavelength in LAB Based Liquid Scintillator
• Separating Double-Beta Decay Events from Solar Neutrino Interactions in a Kiloton-Scale Liquid Scintillator Detector By Fast Timing
• A new CVD Diamond Mosaic-Detector for (n,$\alpha$) Cross-Section Measurements at the n\_TOF Experiment at CERN
• Light Yield of Perovskite Nanocrystal-Doped Liquid Scintillator
• Sensitivity to neutrinos from the solar CNO cycle in Borexino
• Correlated and Integrated Directionality for sub-MeV solar neutrinos in Borexino
• Detecting Cherenkov Light From 1-2 MeV Electrons in Linear Alkylbenzene
• Sensitivity of a low threshold directional detector to CNO-cycle solar neutrinos
• Topological track reconstruction in unsegmented, large-volume liquid scintillator detectors

Cited by in corpus (17)

• Toward the discovery of matter creation with neutrinoless double-beta decay
• Final results of Borexino on CNO solar neutrinos
• Review of Novel Approaches to Organic Liquid Scintillators in Neutrino Physics
• Solar neutrino physics
• Correlated and Integrated Directionality for sub-MeV solar neutrinos in Borexino
• EOS: a demonstrator of hybrid optical detector technology
• Dark sectors in neutron-shining-through-a-wall and nuclear absorption signals
• Axion Helioscopes as Solar Thermometers
• Neutrino astronomy as a probe of physics beyond the Standard Model: decay of sub-MeV $B$-$L$ gauge boson dark matter
• Event-by-Event Direction Reconstruction of Solar Neutrinos in a High Light-Yield Liquid Scintillator
• ${}^{138}\mathrm{Ba}(d,\alpha )$ study of states in ${}^{136}\mathrm{Cs}$: Implications for new physics searches with xenon detectors
• Distinctive nuclear signatures of low-energy atmospheric neutrinos
• CYG$\nu$S: Detecting solar neutrinos with directional gas time projection chambers
• Study of neutron production for 360 GeV cosmic muons
• Searching for beyond-Standard-Model solar neutrino interactions using directional detectors
• New Spallation Background Rejection Techniques to Greatly Improve the Solar Neutrino Sensitivity of JUNO
• Slow-Fluor Scintillator for Low Energy Solar Neutrinos and Neutrinoless Double Beta Decay