TY  - JOUR
AU  - BABAR Collaboration (Lees, J. P. et al
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
PY  - 2019
DA  - 2019//
TI  - Observation of the Decay D-0 -> K- pi(+) e(+) e(-)
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 081802
EP  - 8pp
VL  - 122
IS  - 8
PB  - Amer Physical Soc
AB  - We report the observation of the rare charm decay D-0 -> K-pi(+)e(+)e(-), based on 468 fb(-1) of e(+)e(-) annihilation data collected at or close to the center-of-mass energy of the (sic)(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-pi(+)e(+)e(-)) = (4.0 +/- 0.5 +/- 0.2 +/- 0.1) x 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-pi(+)pi(+)pi(-) 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-pi(+)mu(+)mu(-) 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-pi(+)e(+)e(-)) < 3.1 x 10(-6).
SN  - 0031-9007
UR  - https://arxiv.org/abs/1808.09680
UR  - https://doi.org/10.1103/PhysRevLett.122.081802
DO  - 10.1103/PhysRevLett.122.081802
LA  - English
N1  - WOS:000459920400005
ID  - BABARCollaborationLees_etal2019
ER  -