Related papers: K to \pi\pi\ hadronic matrix elements of left-righ…

We are using domain wall fermions to study $K \to \pi \pi$ matrix elements by measuring $K \to \pi$ and $K \to 0$ matrix elements on the lattice and employing chiral perturbation theory to relate these to the desired physical result. The…

In this work we investigate the implication of $K\to \pi \nu \bar{\nu}$ from the recent KOTO and NA62 measurements for generic neutrino interactions and the new physics scale in effective field theories. The interactions between quarks and…

Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive dispersion relations, such as those relevant in…

We present the ingredients necessary for the determination of physical K->pi pi decay amplitudes for Delta I=3/2 transitions, from lattice simulations at unphysical kinematics and the use of chiral perturbation theory at next-to-leading…

The use of chiral perturbation theory in extracting physical K to pi pi matrix elements from matrix elements calculated at unphysical kinematics is outlined. In particular, the possibility of utilizing pions with non-zero momentum in the…

We make an attempt to clarify the role of the annihilation or "penguin" mode in the description of the $K\rightarrow\pi\pi$ decay within the Standard Model. The attention is concentrated on new operators in the effective $\Delta S=1$…

We present a lattice calculation of the $K\to\pi$ and $K\to 0$ matrix elements of the $\Delta S=1$ effective weak Hamiltonian which can be used to determine $\epsilon^\prime/\epsilon$ and the $\Delta I=1/2$ rule for $K$ decays in the…

We consider the matrix elements of the left-handed flavor-conserving four-quark operators in the nucleon and pion states. Using chiral symmetry, we derive relationships among these matrix elements. We argue that the $\Delta I = 1/2$ rule of…

We calculate the new contribution to the direct CP-violation parameter $\epsilon'$ in $K\to \pi\pi$ decay in the minimal left-right symmetric model with the recently-obtained right-handed quark Cabibbo-Kobayashi-Maskawa mixing. We pay…

We explore application of the domain wall fermion formalism of lattice QCD to calculate the $K\to\pi\pi$ decay amplitudes in terms of the $K\to\pi$ and $K\to 0$ hadronic matrix elements through relations derived in chiral perturbation…

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 perform for the first time a direct calculation of on-shell $K\to\pi\pi$ hadronic matrix elements of chromomagnetic operators (CMO) in the Standard Model and beyond. To his end, we use the successful Dual QCD (DQCD) approach in which we…

The $K\to\pi\pi$ decay amplitudes are studied within the framework of generalized factorization in which the effective Wilson coefficients are gauge-invariant, renormalization-scale and -scheme independent while factorization is applied to…

We calculate for the first time all four-quark hadronic matrix elements of local operators possibly contributing to $K\to\pi\pi$ decays and in particular to the ratio $\epsilon'/\epsilon$ beyond the Standard Model (BSM). To this end we use…

Different scenarios of new physics beyond the standard model give rise to a direct coupling of right-handed quarks to W bosons. We will discuss how the prediction of the Callan-Treiman low energy theorem for the scalar K pi form factor in…

The combined use of chiral $SU(3)$ and heavy quark symmetries allows one to relate the hadronic form factors for the decay $\bar B\to \bar K\e^+\e^-$ to those for $\bar B\to\pi\e^-\bar\nu$. We investigate departures from the symmetry limit…

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. Expanding on the earlier works by Bernard {\it et al.} and by Donini {\it et al.}, we show…

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 proposed to compute matrix elements for the (unphysical) $K^0\pi^-\to \pi^-$ transition to determine the next-to-leading order low energy constants of the weak chiral Lagrangian. This allows us to evaluate $K\to(\pi\pi)_{I=0}$ decay…

We report on the status of our dynamical simulations of a $SU (N_c )$ gauge theory with $N_c=3-6$ and $N_f =4$ fundamental fermions. These ensembles can be used to study the Large $N_c$ scaling of weak matrix elements in the GIM limit…