Related papers: A New Estimate of $\varepsilon '/\varepsilon$

The CP conserved non leptonic $K\to \pi \pi \pi$ decays are discussed within the chiral quark model, including chiral perturbation theory corrections. All amplitudes are parameterized in terms of quark and gluon condensate and the…

The theoretical status of direct CP violation $\epsilon'/\epsilon$ is briefly reviewed. Special attention is paid to the recent new consistent predictions for both the ratio $\epsilon'/\epsilon$ and the $\Delta I = 1/2$ rule within the…

The two most precise determinations of the CKM matrix element V_us are based on the analyses of leptonic and semileptonic kaon decays. These studies also rely on the lattice QCD calculations of two hadronic parameters, namely the ratio of…

Theoretical predictions for inclusive semileptonic B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. This method gives theoretically consistent and…

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…

Effective \Delta S=1 four fermion operators involving left- and right-handed currents are relevant in left-right gauge extensions of the standard model and scalar extension of the Yukawa sector. They induce K to \pi\pi\ decays which are…

The $SU(3)$ chiral effective lagrangian at next-to-leading order is applied to the S-wave meson-baryon interaction in the energy range around the $\eta N$ threshold. Potentials are derived from this lagrangian and used in a coupled channel…

We report on progress and future plans for calculating kaon weak matrix elements for epsilon'/epsilon using staggered fermions.

The weak $\Lambda N\to NN$ transition is studied in the valence quark model approach. The quark component of the two baryon system is described in the quark cluster model and the weak transition potential is calculated by evaluating the…

Pion-kaon ($\pi K$) pairs occur frequently as final states in heavy-particle decays. A consistent treatment of $\pi K$ scattering and production amplitudes over a wide energy range is therefore mandatory for multiple applications: in…

In the chiral limit, the $D=6$ contribution to the Operator Product Expansion (OPE) of the $\mathrm{VV-AA}$ correlator of quark currents only depends on two vacuum condensates, which can be related to hadronic matrix elements associated to…

We overview the detailed analysis of epsilon'/epsilon within the Standard Model, presented in ref. 1. When all sources of large logarithms are considered, both at short and long distances, it is possible to perform a reliable Standard Model…

I calculate the leading logarithmic contributions up to two-loop order of the octet part of the K -> pi pi amplitude. This sector of the weak chiral Lagrangian is believed to be the main source of the enhancement of the I=0 relative to the…

We present results from simulations using 2 flavours of O(a)-improved Wilson quarks whose masses are about 1/3 of the physical strange quark mass. We present new data on the mass of the singlet pseudoscalar meson and evidence of the onset…

We calculate perturbatively the effect of density on hadronic properties using the chiral quark model implemented by the QCD trace anomaly to see the possibility of constructing Lorentz invariant Lagrangian at finite density. We calculate…

We construct an effective Lagrangian of heavy and light mesons with $1/M_Q$ correction. The Lagrangian is constructed model independent way by using only the information of the symmetry of QCD. Reparameterisation invariance at the meson…

We study the |Delta I|=3/2 amplitudes of hyperon non-leptonic decays of the form B->B'+pi in the context of chiral perturbation theory. The lowest-order predictions are determined in terms of only one unknown parameter and are consistent…

We study the scaling of kaon decay amplitudes with the number of colours, $N_c$, in a theory with four degenerate flavours, $N_f=4$. In this scenario, two current-current operators, $Q^\pm$, mediate $\Delta S=1$ transitions, such as the two…

A chiral extrapolation of the light vector meson masses in the up, down and strange quark masses of QCD is presented. We apply an effective chiral Lagrangian based on the hadrogenesis conjecture to QCD lattice ensembles of PACS-CS,…

We give a progress report of our lattice calculation of direct and indirect CP violation in kaon decays, parametrized as $\epsilon'/\epsilon$ and $B_K$, which require non-perturbative calculation of the matrix elements of the Standard Model…