English

Weak phase alpha from B^0-> a_1^{+-}(1260) pi^{-+}

High Energy Physics - Phenomenology 2008-11-26 v2

Abstract

Quasi two-body decays B^0(t)-> a_1^{+-}(1260) pi^{-+} identified by four charged pions determine a phase alpha_eff, which is equal to the weak phase alpha in the limit of vanishing penguin amplitudes. Applying flavor SU(3) to these decays and to B->a_1 K and B->K_1 pi, with K_1 an admixture of K_1(1270) and K_1(1400), we derive expressions providing bounds on alpha-alpha_{eff}. Higher precision in alpha may be achieved by an overall fit to a complete set of SU(3) related measurements. A method is sketched applying isospin symmetry to time-dependent invariant mass distributions in B->pi^+ pi^- pi^0 pi^0.

Keywords

Cite

@article{arxiv.hep-ph/0512148,
  title  = {Weak phase alpha from B^0-> a_1^{+-}(1260) pi^{-+}},
  author = {M. Gronau and J. Zupan},
  journal= {arXiv preprint arXiv:hep-ph/0512148},
  year   = {2008}
}

Comments

4 pages, small changes, to be published in Physical Review D

R2 v1 2026-07-22T14:06:11.926Z