Constraints on the non-standard interaction in propagation from atmospheric neutrinos

Abstract

The sensitivity of the atmospheric neutrino experiments to the non-standard flavor-dependent interaction in neutrino propagation is studied under the assumption that the only nonvanishing components of the non-standard matter effect are the electron and tau neutrino components $ε_{ee}$, $ε_{eτ}$, $ε_{ττ}$ and that the tau-tau component satisfies the constraint $ε_{ττ}=|ε_{eτ}|^2/(1+ε_{ee})$ which is suggested from the high energy behavior for atmospheric neutrino data. It is shown that the Superkamiokande (SK) data for 4438 days constrains $|\tanβ|\equiv|ε_{eτ}/(1+ε_{ee})|\lesssim 0.8$ at 2.5$σ$ (98.8\%) CL whereas the future Hyperkamiokande experiment for the same period of time as SK will constrain as $|\tanβ|\lesssim 0.3$ at 2.5$σ$CL from the energy rate analysis and the energy spectrum analysis will give even tighter bounds on $ε_{ee}$ and $|ε_{eτ}|$.