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 to 0.74 MeV, selected using the dominant scintillation light, we have measured 10 8871(-2103)(+238)(6) (stat) +/- 947(syst) (68% confidence interval) solar neutrinos out of 19 904 total events. This corresponds to a Be-7 neutrino interaction rate of 51.6(-12.5)(+13.9) counts/(day center dot 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.

First Directional Measurement of Sub-MeV Solar Neutrinos with Borexino

Di Noto, L;Pallavicini, M;
2022

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 to 0.74 MeV, selected using the dominant scintillation light, we have measured 10 8871(-2103)(+238)(6) (stat) +/- 947(syst) (68% confidence interval) solar neutrinos out of 19 904 total events. This corresponds to a Be-7 neutrino interaction rate of 51.6(-12.5)(+13.9) counts/(day center dot 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.
File in questo prodotto:
File Dimensione Formato  
Directional_paper_2022_PRL.pdf

accesso aperto

Tipologia: Documento in versione editoriale
Dimensione 715.71 kB
Formato Adobe PDF
715.71 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11567/1077783
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 0
social impact