Under the framework of soft-collinear effective theory, we analyze the charmless B → V V decays in a global way at leading power in 1/m b and leading order in α s with V denoting a light vector meson. In the flavor SU(3) symmetry, decay amplitudes for the 28 decay modes are expressed in terms of 8 nonperturbative parameters. With 35 experimental results, we fit these 8 nonperturbative parameters. Annihilation contributions are neglected due to power suppression in the m b → ∞ limit, so we include in the fit the nonperturbative charm penguins, which will play an important role in understanding the direct CP asymmetries. Charming penguins are also responsible for the large transverse polarizations of penguin-dominated and color-suppressed decays. With the best fitted parameters, we calculate all possible physical observables of 28 decay modes, including branching fractions, direct CP asymmetries, and the complete set of polarization observables. Most of our results are compatible with the present experimental data when available, while the others can be examined on the ongoing LHCb experiment and the forthcoming Belle-II experiment. Moreover, the agreements and differences with results in QCD factorization and perturbative QCD approach are also discussed. A few observables are suggested to discriminate these different approaches. * Weak decays of B mesons can provide us not only an interesting avenue to understand the CP violation and the quark flavor mixing in the standard model (SM), but also a powerful means to probe new physics effects beyond the SM [1,2]. Experimentally, the B meson weak decays have been extensively investigated in the past decades at both e + e − colliders (B-factories) at SLAC and KEK, and hadronic environments such as Tevatron. The experimental results obtained by Babar, Belle, D0 and CDF collaborations have reached an unprecedented precision [3]. In recent years, with the running of LHC at CERN, the LHCb experiment has become the main player of the bottom quark. To date a large amount of bottom meson and baryon events has been accumulated, and a number of results related to non-leptonic decays have been released and more analyses are ongoing [4]. In addition, the forthcoming Belle-II experiment will further improve the experimental precision significantly [5].With the plethora of precise experimental data on nonleptonic decays at hand, theoretical predictions at the same level of accuracy are very much desired. However, for dealing with the hadronic B decays theoretically, the major obstacle is to reliably evaluate the hadronic matrix elements of local operators between the initial and final hadronic states, especially due to the nontrivial QCD dynamics involved. In the past two decades, three major QCD-inspired approaches had been proposed to calculate the charmless non-leptonic B decays, namely, QCD factorization (QCDF) [6], perturbative QCD (PQCD) [7], and soft-collinear effective theory (SCET) [8]. A prominent difference among them resides in the treatment of dynamical degrees of freed...
We analyze charmless two-body non-leptonic B decays B → P P, P V under the framework of factorization assisted topological amplitude approach, where P (V ) denotes a light pseudoscalar (vector) meson. Compared with the conventional flavor diagram approach, we consider flavor SU (3) breaking effect assisted by factorization hypothesis for topological diagram amplitudes of different decay modes, factorizing out the corresponding decay constants and form factors. The non-perturbative parameters of topology diagram magnitudes χ and strong phase φ are universal that can be extracted by χ 2 fit from current abundant experimental data of charmless B decays.The number of free parameters and the χ 2 per degree of freedom are both reduced comparing with previous analysis. With these best fitted parameters, we predict branching fractions and CP asymmetry parameters of nearly 100 B u,d and B s decay modes. The long-standing ππ and πK-CP puzzles are resolved simultaneoulsy. PACS numbers:Recently, an additional Glauber phase is introduced to solve this puzzle [11].Unlike the above mentioned perturbative approaches, some model-independent approaches were introduced to analyze the charmless B decays, such as global SU (3)/U(3) flavor symmetry analysis [12] and flavor topological diagram approach [13, 14]. They do not apply factorization in QCD, leaving all perturbative or non-perturbative QCD effects extracted from experimental data. In [12], they related relevant decay amplitudes using SU(3)/U(3) group decomposition and then extract them form experimental data. For the flavor topological diagram approach, they group different contributions according to the electroweak topological diagram, since electroweak interaction naturally factorize from QCD interaction. Each topological diagram amplitude including all strong interactions with strong phase are to be extracted from experimental data. However, in order to reduce the number of free parameters, it needs to apply the flavor SU(3) symmetry to relate topological diagram parameters of different decay modes. In fact, the flavor SU(3) symmetry is broken.Nowadays, SU(3) breaking effect have to be considered to compare the theoretical results with the precise experimental data. It is also observed in the flavor topological diagram analysis that there are large differences among the three types of B → P P , B → P V and B → V P decays due to different pseudoscalar and vector final states. Therefore, they have to fit three different sets of parameters for the three types of B decays respectively [14].
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