The rate of neutrino-electron elastic scattering interactions from 862 keV 7Be solar neutrinos in Borexino is determined to be 46:0 1:5ðstatÞþ1:5 1:6 ðsystÞ counts=ðday 100 tonÞ. This corresponds to a e-equivalent 7Be solar neutrino flux of ð3:10 0:15Þ 109 cm2 s1 and, under the assumption of e 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 5:0. A global solar neutrino analysis with free fluxes determines pp ¼ 6:06þ0:02 0:06 1010 cm2 s1 and CNO < 1:3 109 cm2 s1 (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.
Precision Measurement of the ^{7}Be Solar Neutrino Interaction Rate in Borexino
CARRARO, CARLO;MANUZIO, GIULIO;PALLAVICINI, MARCO;
2011-01-01
Abstract
The rate of neutrino-electron elastic scattering interactions from 862 keV 7Be solar neutrinos in Borexino is determined to be 46:0 1:5ðstatÞþ1:5 1:6 ðsystÞ counts=ðday 100 tonÞ. This corresponds to a e-equivalent 7Be solar neutrino flux of ð3:10 0:15Þ 109 cm2 s1 and, under the assumption of e 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 5:0. A global solar neutrino analysis with free fluxes determines pp ¼ 6:06þ0:02 0:06 1010 cm2 s1 and CNO < 1:3 109 cm2 s1 (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.
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