Baryon helicity in B decay

The unexpectedly large transverse polarization measured in the B-to-phi K* decay poses the question whether it is accounted for as a strong interaction effect or possibly points to a hidden nonstandard weak interaction. We extend here the perturbative argument to the helicity structure of the two-body baryonic decay and discuss qualitatively on how the baryonic B decay modes might help us in understanding the issue raised by the B-to-VV decays. We find among others that the helicity +1/2 amplitude dominates in the leading order in the B (b-bar q) decay and that the dominant amplitude is sensitive to the right-handed penguin interaction.Comment: References added and typos correcte

Inelastic final-state interaction

The final-state interaction in multichannel decay processes is systematically studied with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like"Watson's theorem" holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases

The X(3872) boson: Molecule or charmonium

It has been argued that the mystery boson X(3872) is a molecule state consisting of primarily D0-D0*bar + D0bar-D*0. In contrast, apparent puzzles and potential difficulties have been pointed out for the charmonium assignment of X(3872). We examine several aspects of these alternatives by semiquantitative methods since quantitatively accurate results are often hard to reach on them. We find that some of the observed properties of X(3872), in particualr, the binding and the production rates are incompatible with the molecule interpretation. Despite puzzles and obstacles, X(3872) may fit more likely to the excited triplet P_1 charmonium than to the molecule after mixing of cc-bar with DD*-bar +Dbar-D* is taken into account. One simple experimental test is pointed out for distinguishing between a charmonium and an isospin-mixed molecule in the neutral B decay.Comment: A few sentences of comment are added. One minor rewording in the Introduction. Two trivial typos are correcte

Branching Ratios Into Kμ2, Ke3, and Ke4 in the Partially Conserved Axial-Vector Current

The partially conserved axial-vector current hypothesis (PCAC) [1] has been successfully applied to the parity-nonconserving amplitudes of the nonleptonic hyperon decays [2] and to the nonleptonic K decays [3]. The ΔI = 1/2 rules are proved for all the processes except Σ decays in the approximation of putting the pion four-momenta equal to zero [4]. In addition, the branching ration K3π/K2π is calculated and found to be in good agreement with experiment

Partially conserved axial-vector current and the nonleptonic K-meson decays

Current commutation relations and a partially conserved axial-vector current hypothesis (PCAC) are applied to the nonleptonic K decays. On the assumption that the effective weak interactions should have the transformation property suggested by Gell-Mann in the quark model of the chiral symmetry, and that the axial-vector isospin charges to which the pions are related through PCAC should be generators of U(2)×U(2), the K2π and the K3π decay amplitudes, in which the four-momenta of all the final pions are continued to zero, are proved to obey the ΔI=1/2 rule. In the approximation of neglecting the continuation, the decay rate of the K3π is related to that of the K2π. The ratio of the decay rates is estimated and a reasonable agreement with experiment is obtained. Only the charge independence is assumed for the strong interactions

Minimal electromagnetic currents and commutation relations

It is pointed out that within the quark model the equal-time commutation relations of currents provide us with a test of minimal electromagnetic interaction of the hadrons. When compared with experiment, the modifications of the Cabibbo-Radicati and Drell-Hearn sum rules resulting from nonminimal interactions may possibly fix the magnitudes of the isoscalar and the isovector Pauli interactions