MHD waves as a source of matter density fluctuations within solar interior

Abstract

It is shown that in the presence of a background magnetic field within solar interior a cavity for low frequency MHD eigen modes (with periods 1-10 days) near equatorial plane can arise. The lower boundary of the cavity coincides with the centre of the Sun while the upper one corresponds to the Alfven resonant layer where high accumulation of wave energy takes place. The localization and the width of the Alfven resonance layer are determined by: (i) the node number of eigen modes n = 1, 2,..., (ii) by the angle of oblique propagation of waves with respect to the magnetic field, and (iii) by a low magnitude of the background magnetic field itself, B=1-100 G. The amplitude of eigen oscillations in a resonant layer determines the density fluctuation value that is restricted through the imaginary part of eigen frequences. For large node numbers n>>1 there appear many narrow resonant layers where a neutrino propagates through a large density fluctuation \delta\rho/\rho with the oscillation length that is much bigger than the width of a resonant layer. It is shown that neutrino crosses many such bumps on the exponential background profile that motivates to consider these MHD waves as a plausible matter noise for the MSW solution to the Solar Neutrino Problem (SNP).