Related papers: Physical matrix elements for Delta I = 3/2 channel…

We compute the leading-order low-energy constants of the DeltaS=1 effective weak Hamiltonian in the quenched approximation of QCD with up, down, strange, and charm quarks degenerate and light. They are extracted by comparing the predictions…

We calculate the hadronic matrix elements to $O(p^4)$ in the chiral expansion for the ($\Delta S =1$) $K^0 \to 2 \pi$ decays and the ($\Delta S=2$) $\bar K^0$-$K^0$ oscillation. This is done within the framework of the chiral quark model.…

Physics beyond the standard model of electroweak interactions that violates lepton number will, in general, induce operators involving the quark and lepton fields that violate lepton number. I point out that some matrix elements of…

We present our result for the $K\to\pi\pi$ decay amplitudes for both the $\Delta I=1/2$ and $3/2$ processes with the improved Wilson fermion action. In order to realize the physical kinematics, where the pions in the final state have finite…

Recent work by J.Prades and myself on $K\to\pi\pi$ is described. The method we use to consistently connect long and short distances is described and numerical results for the $\Delta I=1/2$ rule and on $B_6$, the parameter relevant for the…

The two-body decay rate of a weakly decaying particle (such as the kaon) is shown to be proportional to the square of a well-defined transition matrix element in finite volume. Contrary to the physical amplitude, the latter can be extracted…

We present preliminary results for B_K, B_7^{3/2} and B_8^{3/2} from two high-statistics lattice computations. These calculations are performed at beta=6.0 and 6.2 in the quenched approximation, using mean-field-improved…

We present the ingredients for determining $K^{+}\to\pi^{+}\pi^{0}$ matrix elements via the combination of lattice QCD and chiral perturbation theory ($\chi$PT). By simulating these matrix elements at unphysical kinematics, it is possible…

We report on dispersive and finite energy sum rule analyses of the electroweak penguin matrix elements < (pi pi) | Q_{7,8} | K > in the chiral limit. We accomplish the correct perturbative matching (scale and scheme dependence) at NLO in…

This talk presents results of weak matrix elements calculated from simulations done on 170 $32^3 \times 64$ lattices at $\beta = 6.0$ using quenched Wilson fermions. We discuss the extraction of pseudoscalar decay constants $f_\pi$, $f_K$,…

Isospin breaking correction to the $\Delta I = {1/2}$ decay of $K\to\pi\pi$ generates a large enough contribution to $\epsilon'$ through an induced $\Delta I = {3/2}$ amplitude in $K_L$ decay. Aside from the $\pi$-$\eta$ and $\pi$-$\eta'$…

We compute several matrix elements of dimension-six four-fermion operators and extract their B-parameters. The calculations have been performed with the tree-level Clover action at $\beta = 6.0$. The renormalization constants and mixing…

We study the correlation between $\epe$ and $\Delta I=1/2$ rule in the framework of non-linear $\sigma$ model including scalar mesons. The matrix elements of QCD and Electroweak (EW) penguin operators are computed within factorization…

The coupling constants of the order $p^2$ low-energy weak effective lagrangian can be determined from the $K\to\pi$ and $K\to 0$ weak matrix elements, choosing degenerate quark masses for the first of these. However, for typical values of…

The slope and curvature parameters of the $K\pi$ vector form factor, $F_+^{K\pi}$, are fitted to the data on $\tauKpi$ and $K_{l3}$ decays yielding $\lambda_+'=(25.49 \pm 0.31) \times 10^{-3}$ and $\lambda_+"= (12.22 \pm 0.14) \times…

We report progress in our lattice study of hadronic weak matrix elements relevant for the Delta I = 1/2 rule and epsilon-prime. The presented results are from our first runs on a quenched ensemble with beta=6.0 and a dynamical Nf=2 ensemble…

The $K\to\pi\pi$ system is analyzed in the chiral limit within the Standard Model. We discuss how to connect the short-distance running in the $|\Delta S|=1$ case to the matrix-elements calculated in a low-energy approximation in a…

In kaon decay, electromagnetic radiative corrections can generate shifts in the apparent Delta I = 3/2 amplitude of order alpha A_0/A_2 ~ 22 alpha. In order to know the true Delta I = 3/2 amplitude for comparison with lattice calculations…

Hadronic phase in $\pi \pi$ and $K \bar K$ channels are calculated a la Regge. At the D mass one finds $\delta_{\pi \pi} \approx \pi/3$ and $\delta_{K \bar K} \approx -\pi/6$ in good agreement with the CLEO data while at the B mass these…

We investigate the K1--> K pi pi strong interaction decays. Using the 3P0 quark-pair-creation model to derive the basic parametrization, we discuss in detail how to obtain the various partial wave amplitudes into the possible quasi-two-body…