Search for Rare and Forbidden Decays D^+ --> h^pm e^mp e^+

TL;DR

This study searched for rare and forbidden decay modes of D^+ mesons involving dielectrons, using data from the CLEO-c detector, and set upper limits on their branching fractions due to no observed signals.

Contribution

First search for specific flavor-changing neutral current and lepton-number-violating D^+ decays with new upper limits on their branching fractions.

Findings

No evidence of the targeted decays was found.

Established upper limits on branching fractions at 90% confidence level.

Results constrain new physics models predicting such decays.

Abstract

Using 0.8 million D^+D^- pairs collected with the CLEO-c detector at the psi(3770) resonance, we have searched for flavor-changing neutral current and lepton-number-violating decays of D^+ mesons to final states with dielectrons. We find no indication of either, obtaining 90% confidence level upper limits of B(D^+ -> \pi^+ e^+ e^-) < 7.4 X 10^{-6}$, B(D^+ -> \pi^- e^+ e^+) < 3.6 X 10^{-6}$, B(D^+ -> K^+ e^+ e^-) < 6.2 X 10^{-6}$, and B(D^+ -> K^- e^+ e^+) < 4.5 X 10^{-6}$.