The $a_0(980)$ physics in semileptonic $D^0$ and $D^+$ decays

Abstract

The decays $D^0\to d\bar u\,e^+ν\to a^-_0(980)\, e^+ν\toπ^-η\, e^+ν$ and $D^+\to d\bar d\,e^+ν\to a^0_0(980)\, e^+ν\toπ^0η\, e^+ν$ (and the charge conjugated ones) is the direct probe of the two-quark components in the $a^\pm_0(980)$ and $a^0_0(980)$ wave functions. Recent BESIII experiment is the first step in experimental study of these decays. We present a possible variant of $ηπ$ invariant mass distribution when $a_0(980)$ has no $q\bar q$ component at all.