Stars as Laboratories for Fundamental Physics - MPP Theory Group

368 Chapter 10
Fig. 10.11. Angular distribution of the solar neutrino events at Kamiokande
for 1670 live detector days (January 1987−July 1993), according to Suzuki
(1995). There remains an isotropic background, probably from radioactive
impurities in the water.
Fig. 10.12. Normalized spectra of 8 B neutrinos and of recoil electrons (kinetic
energy T e ) from the elastic scattering process ν e e → eν e .
Even though the Sun is thought to produce only ν e ’s one may speculate
that some of them are converted into ν e ’s on their way to Earth
by spin-flavor oscillations in magnetic fields (Sect. 8.4) or by matterinduced
majoron decays (Sect. 6.8). The ν e ’s would cause a signal by
the reaction ν e p → ne + with an isotropic angular distribution. The
remaining measured isotropic background shown in Fig. 10.11 can thus