Abstract
We report on measurements of the decays of mesons into the semileptonic final states , where represents a or meson and is an electron or a muon. These measurements are based on pairs recorded with the BABAR detector at the SLAC asymmetric factory PEP-II. We determine the branching fraction ratios using events in which the second meson is fully reconstructed. We find and , where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that decays, where denotes either a and meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.
- Received 31 July 2015
DOI:https://doi.org/10.1103/PhysRevLett.116.041801
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