Neutrinos with mixing in twisting magnetic fields

Transitions in a system of neutrinos with vacuum mixing and magnetic moments propagating in matter and a transverse magnetic field are considered. It is shown that in the realistic case of a magnetic field direction varying along the neutrino path qualitatively new phenomena become possible: the permutation of neutrino conversion resonances, appearance of resonances in the neutrino-antineutrino (${\nu }_{\mathrm{lL}}\leftrightarrow {\overline{\nu }}_{\mathrm{lR}}$) transition channels, neutrino-antineutrino resonant conversion, large amplitude ${\nu }_{\mathrm{lL}}\leftrightarrow {\overline{\nu }}_{\mathrm{lR}}$ oscillations, merging of different resonances (triple resonances). The possible phenomenological implications of these effects are briefly discussed.