相关论文: Non-leptonic kaon decays at large $N_c$

The experimental value for the isospin amplitude Re(A_2) in K->pi pi decays has been successfully explained within the Standard Model, both within large N approach to QCD and by QCD lattice calculations. On the other hand in both approaches…

I review recent lattice results in kaon physics, particularly in the determination of V_{us} and the B_K parameter of K^0-\bar{K}^0 mixing. I use lattice data to argue for the need of developing SU(2)_L \times SU(2)_R chiral perturbation…

We investigate the weak kaon-nucleon (NNK) S-wave and P-wave interactions using heavy baryon chiral perturbation theory. The leading 1-loop SU(3) breaking contributions to the $ppK$, $pnK$, and $nnK$ couplings are computed. We find that…

Using Chiral Perturbation Theory to properly account for the dynamics of nonleptonic $K\to 2\,\pi$ decays, we found the Standard Model prediction for the CP violating ratio $\mbox{Re}\left(\varepsilon'/\varepsilon\right)=\left(14\pm…

We study the $\Delta I = 1/2$ rule for kaon decays and the $B_K$ parameter for $K^0 - {\bar K}^0$ mixing in a dual 5-dimensional holographic QCD model. We perform, in the chiral limit, computations of the relevant four-point current-current…

The rare kaon decays $K\to\pi\nu\bar{\nu}$ are strongly suppressed in the standard model and widely regarded as processes in which new phenomena, not predicted by the standard model, may be observed. Recognizing such new phenomena requires…

We analyze long-distance contributions to the K --> pi pi amplitudes relevant for the Delta I = 1/2 selection rule in the framework of the 1/N_c expansion. We use a modified prescription for the identification of meson momenta in the chiral…

We have gained enough statistical precision to distinguish signal from noise in matrix elements of all operators relevant for the Delta I=1/2 rule in kaon decays and for the direct CP violation parameter epsilon-prime. We confirm…

Data indicate that $\Delta I=1/2$ transitions account for 4.5-4.7% of both CP conserving and CP violating $K \to 2\pi$ decays, as well as CP conserving radiative $K \to \pi\pi\gamma$ processes. Observed $K \to \pi\pi\gamma/\pi\pi$ branching…

In Ref [1] we have presented the results of an exploratory lattice QCD computation of the long-distance contribution to the $K^+\to\pi^+\nu\bar{\nu}$ decay amplitude. In the present paper we describe the details of this calculation, which…

The hadronic decays of non-strange negative parity baryons are analyzed in the framework of the 1/Nc expansion. A complete basis of spin-flavor operators for the pseudoscalar meson S and D partial wave amplitudes is established to order…

This review contains an overview of strong interaction effects in weak decays starting with a historical introduction. It contains a short overview of semileptonic decays and their relevance for measuring CKM matrix elements. The main part…

We report on some recent progress made in understanding weak matrix elements of mesons in the context of the next-to-leading order of the large-Nc approximation to QCD. Specifically, we first use the example of the weak contributions to the…

We obtain the corrections in $1/n$ and in $1/\ln n$ ($n$ is the principal quantum number of the bound state) of the decay constants of scalar and pseudoscalar currents in two and four dimensions in the large $N_c$. We obtain them from the…

I review lattice quantum chromodynamics as relevant to the kaon system. Topics covered include the pseudoscalar masses and decay constants, the chiral effective lagrangian, $f_K/f_\pi$, semi-leptonic kaon decay form factors, and the neutral…

We present a lattice QCD calculation of the radiative leptonic decay rates of the kaon, improving upon our previous work, arXiv:2006.05358. Our analysis uses gauge ensembles generated by the Extended Twisted Mass Collaboration (ETMC) with…

Strong upper bounds are derived on certain product combinations of lepton nonconserving couplings in the minimal supersymmetric standard model with explicit $R$-parity violation. The input is information from rare leptonic decays of the…

We study the color-allowed $\Lambda_b\rightarrow \Lambda_c \pi, \Lambda_cK$ decays in the perturbative QCD approach (PQCD) to lowest order in strong coupling constant $\alpha_s$. Both the factorizable and nonfactorizable contributions are…

Three new results are discussed: (a) A non-vanishing amplitude for the `wrong sign{'} kaon decay $B \to J/\Psi \bar{K}$ or its CP conjugate is shown to be a necessary condition for obtaining different CP asymmetries in $B \to J/\Psi…

We present the results of a systematic, first-principles study of the spectrum and decay constants of mesons for different numbers of color charges N, via lattice computations. We restrict our attention to states in the non-zero isospin…