Winter 2003

Winter 2004

In general, the constraints are presented in the parameter spaces (rhobar,etabar), the unitarity triangle angle alpha/phi2, the plane spanned by the observed coefficients of the sine and the cosine terms, (Spipi,Cpipi), as well as the relative strong phase vs. the penguin-to-tree ratio, (|P/T|,delta). It is the goal of the latter two representations to test theoretical approaches used to describe the dynamical structure of the transition amplitudes. A priori knowledge on the CKM phase, obtained from the standard CKM analysis is injected into these fits, either for comparison purposes, or as direct input to predict experimentally accessible observables or theoretical quantities.

We approach the problem following the hierarchical structure outlined below:

1. using as input Spipi and Cpipi as well the BR(B --> pipi) (all charges) and strong isospin symmetry SU(2) and neglecting electro-weak penguins.
2. using I. and B0 --> K+pi- together with SU(3) flavour symmetry and neglecting OZI-suppressed penguin annihilation topologies.
3. using I. and a phenomenological estimate of |P| by means of the decay rate of B+ --> K0pi+. The relative strong phase is unconstrained in this approach.
4. using I. and the prediction of the complex penguin-to-tree ratio, that is |P/T| and its phase, predicted by QCD Factorisation (BBNS).

Details about the analysis can be found in this preprint.

The theoretical description of hadronic charmless B-decays is under ongoing discussions. Therefore, one should consider  these fits as R&D studies when discussing confidence levels. As a consequence, all plots are  marked by an appropriate R&D logo: