2014/03/31 by W.-S. Hou, Wei-Shu Hou, Masaya Kohda +1
Mathematics · Physics and Astronomy · #Algorithm #Annihilation #Asymmetry #Branching fraction #Factorization #High-Energy Particle Collisions Research #Isospin #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #hep-ph
paper · pdf · doi:10.1103/physrevd.90.013002
published as Phys. Rev. D 90, 013002 (2014) · 13 pages, 9 figures; version accepted for publication in PRD; references added
openalex publication_date 2014/07/01 · arxiv created 2014/11/06 · arxiv updated 2014/11/07 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The LHCb experiment observed B+\ensuremath→\ensuremathπ+\ensuremathμ+\ensuremathμ^\ensuremath- decay with 1.0 fb^\ensuremath-1 data, which is the first measurement of a flavor changing neutral current b\ensuremath→d\ensuremathℓ+\ensuremathℓ^\ensuremath- decay (\ensuremathℓ=e,\ensuremathμ). Based on QCD factorization, we give standard model predictions for the branching ratios, direct CP asymmetries, and isospin asymmetry for B\ensuremath→\ensuremathπ\ensuremathℓ+\ensuremathℓ^\ensuremath- decays, in the kinematic region where the dilepton invariant mass is small. We find that the contribution from weak annihilation enhances the direct CP asymmetry for low \ensuremathℓ+\ensuremathℓ^\ensuremath- pair mass. Anticipating improved measurements, we assess the utility of B+\ensuremath→\ensuremathπ+\ensuremathℓ+\ensuremathℓ^\ensuremath- observables, when combined with B0\ensuremath→\ensuremathπ^\ensuremath-\ensuremathℓ+\ensuremathν and B+\ensuremath→K+\ensuremathℓ+\ensuremathℓ^\ensuremath-, for determining Cabibbo-Kobayashi-Maskawa matrix parameters in the future.