Constraining axial non-standard neutrino interactions with MINOS and MINOS+

Abstract

We show that the neutral current data of the MINOS and MINOS+ experiments can provide information on the axial neutral current non-standard interactions of neutrinos with the $u$ and $d$ quarks; {\it i.e.,} on $ε_{αβ}^{Aq}$. We derive bounds on the $ee$, $eτ$ and $ττ$ components of these couplings and show that the MINOS(+) bounds on $ε^{Aq}_{eτ}$ and $ε^{Aq}_{ττ}$ are currently the world leading ones. The bound on the isospin singlet case, $ε^{Au}_{ττ}=ε^{Ad}_{ττ}$ is of particular interest because while this isospin singlet NSI is theoretically motivated, it was practically unconstrained before these results.