Precision Measurement of the Be7 Solar Neutrino Interaction Rate in Borexino

G. Bellini , J. Benziger , D. Bick , S. Bonetti , G. Bonfini , M. Buizza Avanzini , B. Caccianiga , L. Cadonati , F. Calaprice , C. Carraro , P. Cavalcante , A. Chavarria , D. d'Angelo , S. Davini , A. Derbin , A. Etenko , K. Fomenko , D. Franco (1) , C. Galbiati , S. Gazzana , C. Ghiano , M. Giammarchi , M. Goeger-Neff , A. Goretti , L. Grandi , E. Guardincerri , S. Hardy , Aldo Ianni , Andrea Ianni , V. Kobychev , D. Korablev , G. Korga , Y. Koshio , D. Kryn (1) , M. Laubenstein , T. Lewke , E. Litvinovich , B. Loer , F. Lombardi , P. Lombardi , L. Ludhova , I. Machulin , S. Manecki , W. Maneschg , G. Manuzio , Q. Meindl , E. Meroni , L. Miramonti , M. Misiaszek , D. Montanari , P. Mosteiro , V. Muratova , L. Oberauer , M. Obolensky (1) , F. Ortica , M. Pallavicini , L. Papp , C. Peña-Garay , L. Perasso , S. Perasso , A. Pocar , R. S. Raghavan , G. Ranucci , A. Razeto , A. Re , A. Romani , A. Sabelnikov , R. Saldanha , C. Salvo , S. Schönert , H. Simgen , M. Skorokhvatov , O. Smirnov , A. Sotnikov , S. Sukhotin , Y. Suvorov , R. Tartaglia , G. Testera , D. Vignaud (2) , R. B. Vogelaar , F. von Feilitzsch , J. Winter , M. Wojcik , A. Wright , M. Wurm , J. Xu , O. Zaimidoroga , S. Zavatarelli , G. Zuzel

1 APC (UMR_7164) - AstroParticule et Cosmologie
2 APC - Neutrinos

The rate of neutrino-electron elastic scattering interactions from 862 keV Be7 solar neutrinos in Borexino is determined to be 46.0±1.5(stat)-1.6+1.5(syst)counts/(day*100ton). This corresponds to a νe-equivalent Be7 solar neutrino flux of (3.10±0.15)×109cm-2s-1 and, under the assumption of νe transition to other active neutrino flavours, yields an electron neutrino survival probability of 0.51±0.07 at 862 keV. The no flavor change hypothesis is ruled out at 5.0σ. A global solar neutrino analysis with free fluxes determines Φpp=6.06-0.06+0.02×1010cm-2s-1 and ΦCNO<1.3×109cm-2s-1 (95% C.L.). These results significantly improve the precision with which the Mikheyev-Smirnov-Wolfenstein large mixing angle neutrino oscillation model is experimentally tested at low energy.

Mots clés: Solar neutrinos; Decays of heavy neutrinos; Neutrino mass and mixing; Neutrino; muon; pion; and other elementary particle detectors; cosmic ray detectors

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Astrophysique stellaire et solaire [astro-ph.SR]; Astrophysique stellaire et solaire [astro-ph.SR]

G. Bellini, J. Benziger, D. Bick, S. Bonetti, G. Bonfini, et al.. Precision Measurement of the Be7 Solar Neutrino Interaction Rate in Borexino. Physical Review Letters, 2011, 107, pp.141302. ⟨10.1103/PHYSREVLETT.107.141302⟩. ⟨in2p3-00659724⟩