ar X iv : h ep - p h / 99 06 26 9 v 1 6 J un 1 99 9 UK
نویسنده
چکیده
An isospin analysis of B → ππ decays yields sin 2α, where α is the usual CKM angle α ≡ arg[−V td V * tb /(V ud V * ub)] 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 π 0 − 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.
منابع مشابه
ar X iv : h ep - p h / 95 06 25 9 v 1 7 J un 1 99 5 CERN – TH / 95 – 83 hep - ph / 9506259 May 1995 MULTIPLE HARD
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