Hadronic B-Decays

Abstract

Non-leptonic two-body decays are discussed on the basis of a generalized factorization approach. It is shown that a satisfactory description of numerous decay processes can be given using the same two parameters a_1^{eff} and a_2^{eff}. Although in general process-dependent, these parameters are not expected to change markedly. In fact, within error limits, there is no evidence for a process dependence in energetic B-decays. The success of factorization allows the determination of decay constants from non-leptonic decays. For the D_s meson one obtains f_{D_s}=(234\pm25) MeV, for the D^*_s meson f_{D_s^*}=(271\pm33) MeV. The ratio a_2^{eff}/a_1^{eff} is positive in B-decays and negative in D-decays corresponding to constructive and destructive interference in B^- and D^+ decays, respectively. Qualitatively, this can be understood considering the different scales or \alpha_s-values governing the interaction among the outgoing quarks. The running of \alpha_s is also the cause of the observed strong increase of the amplitude of lowest isospin when going to low energy transitions.