Measurement of the $D^0\to K^{-}{\pi }^{+}{e}^{+}{e}^{-}$ branching fraction and search for $D^0\to {\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ and $D^0\to K^{+}{K}^{-}{e}^{+}{e}^{-}$ decays at Belle

Abstract

We present a study of the rare charm meson decays $D^0\to K^{+}{K}^{-}{e}^{+}{e}^{-}$, ${\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$, and $K^{-}{\pi }^{+}{e}^{+}{e}^{-}$ using a 942 fb${}^{-1}$ data set collected by the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. We use $D^0$ candidates identified by the charge of the pion in $D^{\ast }\to D^0\pi$ decays and normalize the branching fractions to $D^0\to K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+}$ decays. The branching fraction for decay $D^0\to K^{-}{\pi }^{+}{e}^{+}{e}^{-}$ is measured to be (39.6 $\pm$ 4.5 (stat) $\pm$ 2.9 (syst)) $\times$ $10^{-7}$, with the dielectron mass in the $\rho /\omega$ mass region $675<m_{ee}<875$ MeV$/c^2$. We also search for $D^0\to h^{-}{h}^{(\prime )+}{e}^{+}{e}^{-}$ ($h^{(\prime )}=K,\pi$) decays with the dielectron mass near the $\eta$ and $\varphi$ resonances, and away from these resonances for the $K^{+}{K}^{-}{e}^{+}{e}^{-}$ and ${\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ modes. For these modes, we find no significant signals and set 90$\%$ confidence level upper limits on their branching fractions at the $\mathcal{O}$(10${}^{-7}$) level.

References in corpus (24)

• PHOTOS Monte Carlo: a precision tool for QED corrections in Z and W decays
• sPlot: a statistical tool to unfold data distributions
• Rare Charm Decays in the Standard Model and Beyond
• The Belle II Core Software
• Flavor & new physics opportunities with rare charm decays into leptons
• Searches for Rare or Forbidden Semileptonic Charm Decays
• On $D\to X_u{l}^{+}{l}^{-}$ within the Standard Model and Frameworks like the Littlest Higgs Model with T Parity
• Standard Model prediction and new physics tests for D0 -> h+h-l+l- (h=π,K; l=e,μ)
• Updated constraints on new physics in rare charm decays
• The New Physics Reach of Null Tests with $D\to \pi \ell \ell$ and $D_s\to K\ell \ell$ Decays
• B2BII - Data conversion from Belle to Belle II
• Null tests from angular distributions in $D\to P_1{P}_2{l}^{+}{l}^{-}$, $l=e,\mu$ decays on and off peak
• Observation of $D^0$ meson decays to ${\pi }^{+}{\pi }^{-}{\mu }^{+}{\mu }^{-}$ and $K^{+}{K}^{-}{\mu }^{+}{\mu }^{-}$ final states
• Search for Rare and Forbidden Charm Meson Decays D0--> V l+ l- and h h l l
• Search for the rare decay ${\Lambda }_c^{+}\to p{\mu }^{+}{\mu }^{-}$
• Search for the rare decays $D\to h(h^{\prime })e^{+}{e}^{-}$
• First observation of the decay $D^0\to K^{-}{\pi }^{+}{\mu }^{+}{\mu }^{-}$ in the ${\rho }^0$-$\omega$ region of the dimuon mass spectrum
• Search for flavor-changing-neutral-current D meson decays
• Observation of the decay $D^0\to K^{-}{\pi }^{+}{e}^{+}{e}^{-}$
• The rare decays of D mesons
• Search for lepton-flavor violating decays $D^0\to X^0{e}^{\pm }{\mu }^{\mp }$
• Search for rare or forbidden decays of the $D^0$ meson
• $S$-wave contribution to rare $D^0\to {\pi }^{+}{\pi }^{-}{\ell }^{+}{\ell }^{-}$ decays in the Standard Model and sensitivity to New Physics
• Search for $D^0$ meson decays to ${\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ and $K^{+}{K}^{-}{e}^{+}{e}^{-}$ final states