Two-body charmless nonleptonic decays of Bu and Bd mesons are studied within the framework of generalized factorization in which the effective Wilson coefficients ceff i are renormalization-scale and -scheme independent while factorization is applied to the tree-level hadronic matrix elements. Contrary to previous studies, our ceff i do not suffer from gauge and infrared problems. Nonfactorizab...

The recently updated measurement of the $W$-boson mass by CDF collaboration exhibits a $7\sigma$ deviation from SM expectation, which may imply sign new physics beyond SM. observed discrepancy could be explained fermions that carry electroweak gauge charges and affect vacuum polarization bosons. Notably, if also have same quantum numbers as quarks, they can mix with latter thus modify penguin d...

We have systematically investigated the semi-inclusive B decays B →MX, which are manifestations of the quark decay b → Mq, within the framework of QCD-improved factorization. These decays are theoretically clean and have distinctive experimental signatures. We focus on a class of these that do not require any form factor information and therefore may be especially suitable for extracting inform...

After updating the determination of the combination of Kobayashi-Maskawa elements Im V ∗ tsVtd according to a new estimate of the parameter B̂K , we study the CP -violating ratio ε/ε by means of hadronic matrix elements computed to O(p4) in the chiral expansion and NLO Wilson coefficients. It is the first time that this order in chiral perturbation theory is included in the analysis. The most im...

Exclusive charmless B decays to η and η are studied in the standard effective Hamiltonian approach. The effective coefficients that take into account nonfactorizable effects in external and internal W -emission amplitudes are fixed by experiment. Factorization is applied to the matrix elements of QCD, electroweak penguin operators and next-to-leading corrections to penguin Wilson coefficients, ...

The exploration of the quark-flavour sector of the Standard Model is one of the hot topics in particle physics of this decade. In these studies, which show a fruitful interplay between theory and experiment, the B-meson system offers a particularly interesting laboratory. After giving an introduction to quark-flavour mixing and CP violation as well as to the theoretical tools to deal with non-l...

The standard model contribution to ǫ/ǫ of the magneticand electric-dipole penguin operators Q11 = gs 16π ms s̄ σμνt G a (1− γ5) d and Q12 = eQd 16π ms s̄ σμνF μν(1− γ5) d is discussed. While the electromagnetic penguin Q12 seems to have a vanishingly small matrix element, we find that the gluonic dipole operator Q11 may give a contribution to ǫ/ǫ comparable to that of other operators so far consi...

Decay rates of B(t) → ππ, B → πK, B → πK (KS → π π) and of charge-conjugate processes are studied within flavor SU(3) symmetry and first-order SU(3) breaking. We show that these measurements can determine with a reasonable accuracy the two angles, α and γ, of the CabibboKobayashi-Maskawa unitarity triangle. B decays provide a variety of CP asymmetry measurements [1], which can test the currentl...