Search for lepton-flavor violating decays $D^0\to X^0{e}^{\pm }\hat{I}{¼}^{\mp }$

Abstract

We present a search for seven lepton-flavor-violating neutral charm decays of the type $D^0\to X^0{e}^{\pm }\hat{I}{¼}^{\mp }$, where $X^0$ represents a $\ddot{I}{€}^0$, $K_{\mathrm{S}}^0$, $\overline{K^{\ast 0}}$, $\ddot{I}{}^0$, $\ddot{I}•$, $\ddot{I}‰$, or $\hat{I}\cdot$ meson. The analysis is based on $468$ fb${}^{-1}$ of $e^{+}{e}^{-}$ annihilation data collected at or close to the $\hat{I}\yen (4S)$ resonance with the BaBar detector at the SLAC National Accelerator Laboratory. No significant signals are observed, and we establish 90\% confidence level upper limits on the branching fractions in the range $(5.0-22.5)\times 10^{-7}$. The limits are between one and two orders of magnitude more stringent than previous measurements.

12 pages, 2 figures, to be submitted to Physical Review D. arXiv admin note: text overlap with arXiv:1905.00608