Measurement of D0→πlν(Klν) Form Factors and Absolute Branching Fractions

Le résumé fourni par la source

Using a $282\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected by the Belle experiment at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ collider, we study ${D}^{0}$ decays to ${K}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ final states. The ${D}^{0}$ flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in ${q}^{2}=({p}_{\ensuremath{\ell}}+{p}_{\ensuremath{\nu}}{)}^{2}$. Normalizing to the total number of ${D}^{0}$ tags, we measure the absolute branching fractions to be $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}K\ensuremath{\ell}\ensuremath{\nu})=(3.45\ifmmode\pm\else\textpm\fi{}{0.07}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.20}_{\mathrm{syst}})%$ and $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\ell}\ensuremath{\nu})=(0.255\ifmmode\pm\else\textpm\fi{}{0.019}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.016}_{\mathrm{syst}})%$ and the semileptonic form factors (within the modified pole model) ${f}_{+}^{K}(0)=0.695\ifmmode\pm\else\textpm\fi{}{0.007}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.022}_{\mathrm{syst}}$ and ${f}_{+}^{\ensuremath{\pi}}(0)=0.624\ifmmode\pm\else\textpm\fi{}{0.020}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.030}_{\mathrm{syst}}$.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.