Experimental tests of factorization in charmless nonleptonic two-bodyBdecays

Abstract

Using a theoretical framework based on the next-to-leading order QCD-improved effective Hamiltonian and a factorization Ansatz for the hadronic matrix elements of the four-quark operators, we reassess branching fractions in two-body non-leptonic decays B → P P, P V, V V , involving the lowest lying light pseudoscalar (P) and vector (V) mesons in the standard model. We work out the parametric dependence of the decay rates making use of the currently available information on the weak mixing matrix elements, form factors, decay constants and quark masses. Using the sensitivity of the decay rates on the effective number of colors, N c , as a criterion of theoretical predictivity, we classify all the current-current (tree) and penguin transitions in five different classes. The recently measured charmless two-body B → P P decays (

The pattern of CP asymmetries inb→stransitions

“…They can lead to a deviation of S f from S ψK and of C f from zero. In Table III we give the values of the a u f parameter (obtained, as explained above, by using factorization [3,4,5]) for all relevant modes. Since we perform our calculations to leading log approximation, we neglect, for consistency, also power corrections within the QCD factorization approach, except for the dominant chirally-enhanced ones related to a 6 and a 8 .…”

“…(15) for each of the three scenarios. We use the factorized decay amplitudes from [3,4,5]. (We use asymptotic distribution amplitudes in the analysis of the scenario with an enhanced chromomagnetic operator.)…”

“…We note, however, differences in the expressions for the f = η (′) K modes between refs. [4] and [5]: A term ∝ f u η (′) (a 6 − 1 2 a 8 ) should be omitted from the first, while a term ∝ f c η (′) (a 7 − a 9 ) should be added to the second.…”

Statistical practice at the Belle experiment, and some questions

“…Table 1: From the η ′ h paper [9]: Branching fraction (BF ) or 90% C.L. limit, and significance (Σ) for Belle, compared with CLEO [11] and BABAR [12] results, and theoretical expectations [13,14]. The branching fractions are in units of 10 −6 .…”

Probing the unparticle signal in b→d penguin processes

“…Now using the QCD coefficients a i 's from [10], the value of the form factor F 0 (m 2 K ) obtained using light cone QCD sum rule approach [11], the particle masses, lifetime of B 0 and K meson decay constant f K = 0.16 GeV taken from [5], the CKM matrix elements as |V tb | = 0.999125,…”