ABSTRACT
The combined effect of matter and magnetic fields on neutrino spin and flavor precession is examined. We find a potential new kind of resonant solar-neutrino conversion veL → vθR or vTR (for Dirac neutrinos) or v e → v ¯ m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429502811/9013a8df-12a2-4548-ae15-6912d69fa9fa/content/inequ90_1.tif"/> or v ¯ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429502811/9013a8df-12a2-4548-ae15-6912d69fa9fa/content/inequ90_2.tif"/> (for Majorana neutrinos). Such a resonance could help account for the lower than expected solar-neutrino ve , flux and/or indications of an anticorrelation between fluctuations in the ve flux and sunspot activity. Consequences of spin-flavor precession for supernova neutrinos are also briefly discussed.
