Related papers: Progress in $K\to\pi\pi$ Decays

I summarize the status of the $\Delta I=1/2$ rule in $K\to\pi\pi$ decays within an {\it analytic} approach based on the dual representation of QCD as a theory of weakly interacting mesons for large $N$, where $N$ is the number of colours.…

We discuss the matching between long-distance and short-distance at next-to-leading in $1/N_c$ and show how the scheme-dependence from the two-loop renormalization group running can be treated. We then use this method to study the three…

We present a calculation of the low energy constants describing the real and imaginary parts of the $K \to \pi \pi$ decay amplitudes $A_0$ and $A_2$. Leading and next leading order chiral perturbation theory is used and its applicability…

The decay $B^- \to K^- K^- \pi^+$ has been sugested as a test for minimal supersymmetric standard model and for supersymmetric models with R-parity violating couplings, in view of its extreme smallnesss in the standard model. We calculate…

We present a status report on our study of long-distance contributions to the decay amplitudes A(K^0 --> pi pi, I) in the framework of the 1/N expansion. We argue that a modified prescription for the identification of meson momenta in the…

We present a calculation of the $K\to\pi\pi$ decay amplitudes from the $K\to\pi$ matrix elements using leading order relations derived in chiral perturbation theory. Numerical simulations are carried out in quenched QCD with the domain-wall…

It is shown that the low energy coefficients of the next-to-leading order (NLO) chiral perturbation theory needed to determine $\Delta I=1/2$, $K\to\pi\pi$ decay amplitudes can be fixed by calculating $K\pi\to\pi$ amplitudes on lattice.…

QCD penguins are responsible for about 2/3 of the Delta I=1/2 rule in K to pi pi decays, as inferred from a combined analysis of K to pi pi and KL to gamma gamma. Further tests based on the decays KS to pi0 gamma gamma and K+ to pi+ gamma…

Trace Anomaly Dominance in weak $K$-decays successfully reproduces the $\Delta I = {1\over 2}$ selection rule results, as observed in $K_S \to \pi\pi, K_L \to \pi\pi\pi, K_S \to \gamma\gamma$ and $K_L \to \pi^0 \gamma\gamma$.

We discuss the theoretical and experimental status of the CP violating ratio eps'/eps. We revise our 1997 standard-model estimate-based on hadronic matrix elements computed in the chiral quark model up to O(p^4) in the chiral expansion-by…

I shortly review the present status of the theoretical calculations of eps'/eps and the comparison with the present experimental results. I discuss the role of higher order chiral corrections and in general of non-factorizable contributions…

We study a new $K\rightarrow\pi\pi$ decay channel with gluons in intermediate state which is normally neglected within the factorization framework. Both short-distance and long-distance parts of the amplitude are calculated. The chiral…

In this talk I describe work on computing non-leptonic matrix elements consistently with both long and short distance contributions included. On the simpler example of the $\pi^+$-$\pi^0$ mass difference I explain in detail the matching…

Rare weak decays of $\eta^\prime\to K\pi$ have been investigated in the framework of the $U(3)$ chiral perturbation theory at the leading order. Our study shows that the branching ratio ${\cal B}(\eta^\prime\to K\pi)$ is of the order of…

After a short summary of my talk, I discuss $K_{l3}$ decays and elastic $\pi\pi$ scattering in the framework of chiral perturbation theory.

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.…

We discuss a potential discrepancy in an approximate relation among $B \to K \pi$ rates which, with increased statistical significance, would imply new physics in $\Delta I=1$ transitions. An approximate relation between CP-violating rate…

We use a twice-subtracted partial-wave dispersion relation in the elastic unitarity approximation for final-state interactions to study the amplitude for the delta I = 1/2 CP-conserving weak process K+spurion->pi+pi. We use a simple…

We present a model-independent analysis of $K^+\to\pi^+\ell^+\ell^-$ and $K_S\to\pi^0\ell^+\ell^-$ decays, including $K\to 3 \pi$ unitarity corrections and a general decomposition of the dispersive amplitude. From the existing data on…

Predictions based on the chirally normalized vector meson dominance model for decay rates and distributions of $\tau$ decays into $K\pi\pi\nu_\tau$ final states are discussed. Disagreements with experimental results can be traced back to…