Search for the rare decays of $D\to h(h^{{(}^{\prime })})e^{+}{e}^{-}$

Abstract

We search for 15 rare decays of $D$ mesons to hadrons accompanied by an electron-positron pair $D\to h(h^{{(}^{\prime })})e^{+}{e}^{-}$, based on 20.3 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector at BEPCII. No significant signals are observed, and the corresponding upper limits on the branching fractions at the 90\% confidence level are determined. The sensitivities of the results are at the level of $10^{-6}$ $\sim$ $10^{-7}$. The upper limits on the branching fractions for the $D^{+}\to \ddot{I}{}^{+}{e}^{+}{e}^{-}$, $D^{+}\to K^{\ast +}{e}^{+}{e}^{-}$, $D^0\to K_S^0{K}_S^0{e}^{+}{e}^{-}$, $D^0\to \ddot{I}{€}^0\ddot{I}{€}^0{e}^{+}{e}^{-}$ and $D^0\to \hat{I}{\cdot }^{\prime }{e}^{+}{e}^{-}$ decay channels are measured for the first time. For the $D^0\to \ddot{I}{€}^0{e}^{+}{e}^{-}$, $D^0\to \hat{I}\cdot e^{+}{e}^{-}$, $D^0\to \ddot{I}‰e^{+}{e}^{-}$, $D^0\to K_S^0{e}^{+}{e}^{-}$, $D^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0{e}^{+}{e}^{-}$, $D^{+}\to K^{+}\ddot{I}{€}^0{e}^{+}{e}^{-}$, $D^{+}\to \ddot{I}{€}^{+}{K}_S^0{e}^{+}{e}^{-}$ and $D^{+}\to K^{+}{K}_S^0{e}^{+}{e}^{-}$ decay channels, the upper limits on the branching fractions are determined, with an improvement of at least a factor of four compared to previous searches. The upper limits on the branching fractions for the $D^0\to \ddot{I}{}^0{e}^{+}{e}^{-}$ and $D^0\to \ddot{I}•e^{+}{e}^{-}$ decay channels are set at $0.7\times 10^{-6}$ and $4.6\times 10^{-6}$, respectively.