Perturbation Theory of Neutrino Oscillation with Nonstandard Neutrino Interactions

Understand

We discuss various physics aspects of neutrino oscillation with non-standard interactions (NSI).

• We formulate a perturbative framework by taking \Delta m^2_{21} / \Delta m^2_{31}, s_{13}, and the NSI elements \epsilon_{\alpha \beta} (\alpha, \beta = e, \mu, \tau) as small expansion parameters of the same order \epsilon.
• Within the \epsilon perturbation theory we obtain the S matrix elements and the neutrino oscillation probability formula to second order (third order in \nu_e related channels) in \epsilon.
• The formula allows us to estimate size of the contribution of any particular NSI element \epsilon_{\alpha beta} to the oscillation probability in arbitrary channels, and gives a global bird-eye view of the neutrino oscillation phenomena with NSI.