2004/02/29 by Bhag C. Chauhan, Bhag C Chauhan, Joao Pulido · 1 citation
Physics and Astronomy · #Context (archaeology) #Dark Matter and Cosmic Phenomena #Flavour #Magnetic field #Neutrino #Neutrino Physics Research #Neutrino oscillation #Precession #Solar and Space Plasma Dynamics #Solar neutrino #Spin (aerodynamics) #hep-ph
paper · pdf · doi:10.1088/1126-6708/2004/06/008
published as JHEP 0406:008,2004 · References updated. Final version to be published in JHEP
arxiv created 2004/06/08 · openalex publication_date 2004/06/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Open questions remain after the confirmation of LMA as the dominant solution to the solar neutrino deficit. These are the apparent time modulation of the solar neutrino event rates in the Homestake, Gallium and SuperKamiokande experiments, possibly related to solar magnetic activity, the discrepancy between the event rate in the Homestake experiment and its theoretical prediction and the absence of the electron spectrum upturn in SuperKamiokande at energies below 6-8 MeV. We search for a possible understanding of these questions in the context of resonant spin flavour precession to sterile neutrinos, assuming a class of magnetic field profiles anchored in the upper radiation/lower convection zone. We consider the simplest such model beyond the standard 2ν flavour LMA one, with one single magnetic moment transition between active and sterile state and vanishing vacuum mixing. The preferred mass square difference is Δm210=O(10-8eV2). The Ga rate appears to be the most sensitive of all to solar activity. It is also found that a field profile extending within a longer region in the radial direction is favoured over another with a shorter span, and leads to a stronger suppression than in the LMA case of the intermediate energy neutrinos and some of the 8 B ones.