Towards a precision determination of α in B→ππ decays -: art. no. 034015

An assumption of isospin symmetry permits the determination of sin(2 alpha) from the experimental study of B ->pi pi decays. Isospin, however, is merely an approximate symmetry; its breaking predicates a theoretical systematical error sigma(alpha)(IB) in the extraction of alpha. We focus on the impact of pi(0)-eta,eta' mixing, as well as the manner in which it is amenable to empirical constraint, and determine that sigma(alpha)(IB) can potentially be controlled to O(1 degrees).