Test of Lepton-Flavor Universality in B →k??+?- Decays at Belle
Journal
Physical Review Letters
Journal Volume
126
Journal Issue
16
Date Issued
2021
Author(s)
Wehle S
Abstract
We present a measurement of RK?, the branching fraction ratio B(B→K?μ+μ-)/B(B→K?e+e-), for both charged and neutral B mesons. The ratio for the charged case RK?+ is the first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass q2. The analysis is based on a data sample of 711 fb-1, containing 772×106 BB¯ events, recorded at the ?(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. The obtained results are consistent with standard model expectations. ? 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Subjects
Atomic physics; Physics; Absolute branching fractions; Asymmetric energy; Belle detectors; Branching fractions; E+e- collider; Invariant mass; Lepton-flavor; Standard model; High energy physics; article; expectation; flavor; lepton
Type
journal article