NEUTRINOS WITH MIXING IN TWISTING MAGNETIC-FIELDS

Transitions in a system of neutrinos with vacuum mixing and magnetic m oments propagating in matter and a transverse magnetic field are consi dered. It is shown that in the realistic case of a magnetic field dire ction varying along the neutrino path qualitatively new phenomena beco me possible: the permutation of neutrino conversion resonances, appear ance of resonances in the neutrino-antineutrino (nu(lL) <-- --> nu(lR) BAR) transition channels, neutrino-antineutrino resonant conversion, l arge amplitude nu(lL) <-- --> nu(lR)BAR oscillations, merging of diffe rent resonances (triple resonances). The possible phenomenological imp lications of these effects are briefly discussed.