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 $$\epsilon _{\alpha \beta }^{Aq}.$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>ϵ</mml:mi> <mml:mrow> <mml:mi>α</mml:mi> <mml:mi>β</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>Aq</mml:mi> </mml:mrow> </mml:msubsup> <mml:mo>.</mml:mo> </mml:mrow> </mml:math> We derive bounds on the ee , $$e\tau $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>e</mml:mi> <mml:mi>τ</mml:mi> </mml:mrow> </mml:math> and $$\tau \tau $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>τ</mml:mi> <mml:mi>τ</mml:mi> </mml:mrow> </mml:math> components of these couplings and show that the MINOS(+) bounds on $$\epsilon ^{Aq}_{e\tau }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>ϵ</mml:mi> <mml:mrow> <mml:mi>e</mml:mi> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>Aq</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> and $$\epsilon ^{Aq}_{\tau \tau }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>ϵ</mml:mi> <mml:mrow> <mml:mi>τ</mml:mi> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>Aq</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> are currently the world leading ones. The bound on the isospin singlet case, $$\epsilon ^{Au}_{\tau \tau }=\epsilon ^{Ad}_{\tau \tau }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>ϵ</mml:mi> <mml:mrow> <mml:mi>τ</mml:mi> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>Au</mml:mi> </mml:mrow> </mml:msubsup> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mi>ϵ</mml:mi> <mml:mrow> <mml:mi>τ</mml:mi> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>Ad</mml:mi> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> is of particular interest because while this isospin singlet NSI is theoretically motivated, it was practically unconstrained before these results.