Paper detail

Charm Decays and Spectroscopy at BABAR

We present searches for rare charm decays of the form $X_c^+ \to h^{\pm} \ell^{\mp} \ell^{(')^+}$, where $X_c^+$ is a charm hadron either $D^+$, $D_s^+$, or $Λ_c^+$, and $\ell^{(')^{\pm}}$ is an electron or muon. These modes are based on 384 $fb^{-1}$ of $e^+ e^-$ annihilation data collected at the $Υ(4S)$ resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We also present the flavor-changing neutral-current decays $D^0 \to e^+e^-$, $D^0 \to μ^+ μ^-$, and $D^0 \to e^{\pm} μ^{\mp}$ that corresponds to an integrated luminosity of 468 $fb^{-1}$ of data. The decay $D^0 \to e^+ μ^-$ is further lepton-flavor violating, and thus occur only through very slow neutrino mixing. These decays constitute sensitive probes for possible new-physics contribution. We report new limits on the branching fractions of these decays.