Abstract
A measurement of the ratio of the branching fractions of the and decays is presented using proton-proton collision data, corresponding to an integrated luminosity of , recorded with the LHCb experiment at center-of-mass energies of 7 and 8 TeV. The value of the ratio of branching fractions for the dilepton invariant mass squared range is measured to be . This value is the most precise measurement of the ratio of branching fractions to date and is compatible with the standard model prediction within 2.6 standard deviations.
- Received 25 June 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.151601
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Published by the American Physical Society
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