2014/02/05 by Benjamı́n Grinstein, Benjamín Grinstein, David Pirtskhalava +3 · 9 citations
Mathematics · Physics and Astronomy · #Amplitude #Combinatorics #Computer science #Hamiltonian (control theory) #Isospin #Mathematical physics #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Similarity (geometry) #Tree (set theory) #hep-ph
paper · pdf · doi:10.1103/physrevd.89.114014
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 89(11) (American Physical Society) · 10 pages, 5 figures
arxiv created 2014/02/05 · openalex publication_date 2014/06/11 · arxiv updated 2014/06/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We perform an isospin analysis of B decays to two pseudoscalars. The analysis extracts appropriate Cabbibo-Kobayashi-Maskawa matrix elements and short distance loop factors to allow for comparison of nonperturbative QCD effects in the reduced matrix elements of the amplitudes. In decays where penguin diagrams compete with tree-level diagrams we find that the reduced matrix elements of the penguin diagrams, which are singlets or doublets under isospin, are significantly enhanced compared with the triplet and fourplet contributions of the weak Hamiltonian. This similarity to the \mathrm\ensuremathΔI=(1)/(2) rule in K\ensuremath→\ensuremathπ\ensuremathπ decays suggests that, more generally, processes mediated by Hamiltonians in lower-dimensional isospin representations see enhancement over higher-dimensional ones in QCD.