QCD FACTORIZATION BASED ON SIX-QUARK OPERATOR EFFECTIVE HAMILTONIAN FROM PERTURBATIVE QCD AND CHARMLESS BOTTOM MESON DECAYS B(s)→ππ, πK, KK

The charmless bottom meson decays are systematically investigated based on an approximate six-quark operator effective Hamiltonian from perturbative QCD. It is shown that within this framework the naive QCD factorization method provides a simple way to evaluate the hadronic matrix elements of two-body mesonic decays. The singularities caused by on mass-shell quark propagator and gluon exchanging interaction are appropriately treated. Such a simple framework allows us to make theoretical predictions for the decay amplitudes with reasonable input parameters. The resulting theoretical predictions for all the branching ratios and CP asymmetries in the charmless B0, B+, Bs → ππ, πK, KK decays are found to be consistent with the current experimental data except for a few decay modes. The observed large branching ratio in B→π0π0 decay remains a puzzle though the predicted branching ratio may be significantly improved by considering the large vertex corrections in the effective Wilson coefficients. More precise measurements of charmless bottom meson decays, especially on CP violations in B → KK and Bs → ππ, πK, KK decay modes, will provide a useful test and guide us to a better understanding on perturbative and nonperturbative QCD.

Baryon Number Nonconservation and the Stability of Strange Matter

If baryon number nonconservation exists in the form of an effective six-quark operator which also changes strangeness by four units, it could have a tremendous impact on the absolute stability of strange quark matter. We show that such an operator is negligible in the supersymmetric standard model with [Formula: see text] terms in the superpotential, but may be of importance in models with exotic particle content. From the experimental lower limit of 1025 years on the stability of nuclei, we find a model-independent lower limit of the order 105 years on the stability of strange matter against such decays.