Constraining axial non-standard neutrino interactionswith 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; i.e., on $$\epsilon _{\alpha \beta }^Áq}.$$ ϵ α β Aq . We derive bounds on the ee, $$e\tau $$ e τ and $$\tau \tau $$ τ τ components of these couplings and show that the MINOS(+) bounds on $$\epsilon ^Áq}_é\tau }$$ ϵ e τ Aq and $$\epsilon ^Áq}_{\tau \tau }$$ ϵ τ τ Aq are currently the world leading ones. The bound on the isospin singlet case, $$\epsilon ^Áu}_{\tau \tau }=\epsilon ^Ád}_{\tau \tau }$$ ϵ τ τ Au = ϵ τ τ Ad is of particular interest because while this isospin singlet NSI is theoretically motivated, it was practically unconstrained before these results.