Neutrino spin-flip effects in collapsing stars
Neutrino spin-flip effects in collapsing stars
We study the spin-flavor transitions of neutrinos, \ensuremath{\nu}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{e}}$-${\ensuremath{\nu}}_{\mathrm{\ensuremath{\mu}}}$, ${\ensuremath{\nu}}_{\mathit{e}\mathrm{\ensuremath{-}}}$\ensuremath{\nu}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathrm{\ensuremath{\mu}}}$, etc., in the magnetic fields of a collapsing star. For the neutrino mass squared difference \ensuremath{\Delta}${\mathit{m}}^{2}$\ensuremath{\sim}(${10}^{\mathrm{\ensuremath{-}}10}$--10) ${\mathrm{eV}}^{2}$ the transitions take place in an almost isotopically neutral region of the star, where the effective matter density is suppressed up to 3--4 orders …