Sensitivity of T2KK to the non-standard interaction in propagation

Abstract

Assuming only the non-zero electron and tau neutrino components $ε_{ee}$, $ε_{eτ}$, $ε_{ττ}$ of the non-standard matter effect and postulating the atmospheric neutrino constraint $ε_{ττ}=|ε_{eτ}|^2/(1+ε_{ee})$, we study the sensitivity to the non-standard interaction in neutrino propagation of the T2KK neutrino long-baseline experiment. It is shown that T2KK can constrain the parameters $|ε_{ee}|\lesssim 1$, $|ε_{eτ}|\lesssim 0.2$. It is also shown that if $|ε_{eτ}|$ and $θ_{13}$ are large, then T2KK can determine the Dirac phase and the phase of $ε_{eτ}$ separately, due to the information at the two baselines. We also provide an argument that the components $|ε_{αμ}|$ $(α=e,μ,τ)$ must be small for the disappearance oscillation probability to be consistent with high-energy atmospheric neutrino data, which justifies our premise that these quantities are negligible.