Companion appendix to BCT Letter 86. Provides the formal statement and proof of the BCT Cabibbo Theorem: sin (θC) = 2rₜet (1+3α0/8), where rₜet = (√6−2) /4 is the tetrahedral void radius and α0 = rₒct·rₜet/π is the BCT bare coupling. Contains: the complete closed-form algebraic expression for sin (θC) in √2, √6 and π with zero numerical inputs; full derivation of the two-generation CKM block from unitarity; the structural parallel between the Weinberg angle (intra-generation, NLO factor 9α0/4) and the Cabibbo angle (inter-generation, NLO factor 3α0/8) ; and a candidate for the Wolfenstein A parameter: A ≈ 1/ (1+rₒct), error +0. 56%, formal derivation deferred to Appendix AD2.
Michel Robert Cabrie (Sun,) studied this question.
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