Neutrino oscillations in matter with varying density

by Dr Ara Ioannisian (Yerevan Physics Institute)

Friday 11 Jul 2008, 14:00 → 15:00 Europe/Zurich

TH Theory Conference Room (CERN)

We present a new formalism for description of neutrino oscillations in matter with varying density which is both accurate and has all advantages of a full analytic treatment. The formalism is based on the generalized Baker-Campbell-Hausdorff (Magnus) expansion. The formulas can be applied for propagation of the solar and supernova neutrinos in matter of the Earth, substantially simplifying numerical calculations. Various expansions are obtained depending on basis of neutrino states and a way to split the Hamiltonian into the self-commuting and non-commuting parts. We apply the formalism to neutrino oscillations in matter of the Earth and show that the second order of the expansion has better than 3% accuracy up to E \sim 90 MeV for solar \Delta m^2 and up to 2.5 GeV for atmospheric \Delta m^2. Using these formulas we study sensitivity of the oscillation effects to structures of the density profile situated at different distances from the detector.

Slides cerntalk.pdf