1999/06/06 by Susan Gardner, S. Gardner, Gardner, S.
Computer Science · Physics and Astronomy · #Algorithms and Data Compression #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9906269
7 pages, REVTeX, epsf, 1 eps figure, talk at DPF'99
arxiv created 1999/06/06 · openalex publication_date 1999/06/06 · arxiv updated 2009/11/30 · openalex created_date 2020/05/21 · openalex updated_date 2026/07/28
An isospin analysis of B→ ππ decays yields sin 2α, where α is the usual CKM angle α≡ \rm arg [-Vtd Vtb^∗/(VudVub^∗)] without hadronic uncertainty if isospin is a perfect symmetry. Yet isospin symmetry is broken not only by electroweak effects but also by the u and d quark mass difference --- the latter drives π0-η,η' mixing and converts the isospin-perfect triangle relation between the B→ ππ amplitudes to a quadrilateral. The error incurred in sin 2α through the neglect of the resulting isospin-violating effects can be significant, particularly if sin 2α is small.