1999/03/22 by Dan Pirjol · 1 citation
Physics and Astronomy · #Atomic and Subatomic Physics Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.60.054020
published as Phys.Rev. D60 (1999) 054020 · 10 pages ReVTeX with 3 included eps figures
arxiv created 1999/03/22 · openalex publication_date 1999/08/04 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
In the absence of QCD penguin contributions a measurement of the time-dependent asymmetry in the decay B0(t)\ensuremath→\ensuremathπ+\ensuremathπ^\ensuremath- gives directly the weak angle \ensuremathα. Several bounds have been proposed in the literature on the magnitude of the penguin effects on this determination, the prototype of which is the isospin bound of Grossman and Quinn. We point out that large strong final state interactions could cause these bounds to overestimate the real penguin effect. A new flavor SU(3) bound is proposed, requiring only the charge-averaged branching ratios for B0\ensuremath→\ensuremathπ+\ensuremathπ^\ensuremath- and Bs\ensuremath→K+K^\ensuremath-, which exactly takes into account all relevant amplitudes and electroweak penguin effects. This bound on the penguin-induced error on the determination of the weak phase \ensuremathα holds even without knowledge of direct CP asymmetry in the \ensuremathπ+\ensuremathπ^\ensuremath- channel.