Observation of the Decay <i>D</i><SUP>0</SUP> → <i>K</i><SUP>-</SUP> π<SUP>+</SUP> <i>e</i><SUP>+</SUP> <i>e</i><SUP>-</SUP>

Lees, JP, Poireau, V, Tisserand, V, Grauges, E, Palano, A, Eigen, G, Brown, DN, Kolomensky, Yu G, Fritsch, M, Koch, H
et al (show 228 more authors) (2019) Observation of the Decay <i>D</i><SUP>0</SUP> → <i>K</i><SUP>-</SUP> π<SUP>+</SUP> <i>e</i><SUP>+</SUP> <i>e</i><SUP>-</SUP>. PHYSICAL REVIEW LETTERS, 122 (8). 081802-.

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We report the observation of the rare charm decay D^{0}→K^{-}π^{+}e^{+}e^{-}, based on 468  fb^{-1} of e^{+}e^{-} annihilation data collected at or close to the center-of-mass energy of the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We find the branching fraction in the invariant mass range 0.675<m(e^{+}e^{-})<0.875  GeV/c^{2} of the electron-positron pair to be B(D^{0}→K^{-}π^{+}e^{+}e^{-})=(4.0±0.5±0.2±0.1)×10^{-6}, where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty in the branching fraction of the decay D^{0}→K^{-}π^{+}π^{+}π^{-} used as a normalization mode. The significance of the observation corresponds to 9.7 standard deviations including systematic uncertainties. This result is consistent with the recently reported D^{0}→K^{-}π^{+}μ^{+}μ^{-} branching fraction, measured in the same invariant mass range, and with the value expected in the standard model. In a set of regions of m(e^{+}e^{-}), where long-distance effects are potentially small, we determine a 90% confidence level upper limit on the branching fraction B(D^{0}→K^{-}π^{+}e^{+}e^{-})<3.1×10^{-6}.

Item Type: Article
Uncontrolled Keywords: <i>B</i><span class="sc"><i>a</i></span><i>B</i><span class="sc"><i>ar</i></span> Collaboration
Depositing User: Symplectic Admin
Date Deposited: 14 Mar 2019 15:51
Last Modified: 18 Oct 2023 15:48
DOI: 10.1103/PhysRevLett.122.081802
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3034238