Study of the Decay D0→K¯0π−e+νe

We report a study of the decay ${D}^{0}\ensuremath{\rightarrow}{\overline{K}}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$ based on a sample of $2.93\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. The total branching fraction is determined to be $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{\overline{K}}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})=(1.434\ifmmode\pm\else\textpm\fi{}0.029(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.032(\mathrm{syst}.))%$, which is the most precise to date. According to a detailed analysis of the involved dynamics, we find this decay is dominated with the ${K}^{*}(892{)}^{\ensuremath{-}}$ contribution and present an improved measurement of its branching fraction to be $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{*}(892{)}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})=(2.033\ifmmode\pm\else\textpm\fi{}0.046(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.047(\mathrm{syst}.))%$. We further access their hadronic form-factor ratios for the first time as ${r}_{V}=V(0)/{A}_{1}(0)=1.46\ifmmode\pm\else\textpm\fi{}0.07(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.02(\mathrm{syst}.)$ and ${r}_{2}={A}_{2}(0)/{A}_{1}(0)=0.67\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.01(\mathrm{syst}.)$. In addition, we observe a significant ${\overline{K}}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}\text{ }\text{ }S$-wave component accounting for $(5.51\ifmmode\pm\else\textpm\fi{}0.97(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.62(\mathrm{syst}.))%$ of the total decay rate.