Related papers: Improved estimates of rare K decay matrix-elements…
The importance of rare $K$ decays especially in the context of a kaon unitarity triangle (KUT) is emphasized. The decay $K_L \to \pi^0 \nu \bar \nu$ is theoretically very clean but experimentally extremely challenging. The Standard Model…
In this work, we suggest that hard-pion chiral perturbation theory may be applicable to the real parts of nonleptonic B^{+} to D^{0}P^{+} and B^{+} to Dbar^{0}P^{+} (P=K,pi) decay amplitudes. These amplitudes play an important role in the…
The decays $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$, being the theoretically cleanest rare decays of mesons, are very sensitive probes of New Physics. In view of the excellent prospects of reaching the Standard Model sensitivity…
We use chiral perturbation theory to evaluate the scattering amplitude for the process Pi^+ K^- to Pi^+ K^- at leading and next-to-leading orders in the chiral counting and in the presence of isospin breaking effects. We also discuss the…
We study nonperturbative corrections up to O(1/m_b^3) in the inclusive rare B decay B -> X_s l^+ l^- by performing an operator product expansion. The values of the matrix elements entering at this order are unknown and introduce…
In the first part of these lectures, I consider chiral perturbation theory in the presence of matter fields. It allows to systematically work out the consequences of the broken chiral symmetry of QCD. As examples, threshold pion photo- and…
An analysis of electromagnetic corrections to the (dominant) octet K -> pi pi hamiltonian using chiral perturbation theory is carried out. Relative shifts in amplitudes at the several per cent level are found.
We calculate the form factors of the $K \to \pi l \nu$ semileptonic decays in three-flavor lattice QCD, and study their chiral behavior as a function of the momentum transfer and the Nambu-Goldstone boson masses. Chiral symmetry is exactly…
We review some recent theoretical results on rare kaon decays. Particular attention is devoted to establish the short distance (direct CP violating) contribution to K_L => \pi^0 e \bar{e}. This is achieved by a careful study of the long…
By employing the perturbative QCD(pQCD) factorization approach, we calculated the partial next-to-leading order (NLO) contributions to $B_s \to P P$ decays ($P= \pi, K, \etap $), coming from the QCD vertex corrections, the quark-loops and…
We calculate the ratios R_{e/mu}^{(P)} = Gamma(P -> e nu)/Gamma (P -> mu nu) (P=pi,K) in Chiral Perturbation Theory to order e^2 p^4. We complement the one- and two-loop effective theory results with a matching calculation of the local…
The effective theory based on combined chiral and heavy quark symmetry (HHChPT) is applied to D meson decays. The predictions for several flavor changing neutral current rare radiative charm decays are given both in the Standard Model as…
The long-distance contributions to $K\to 2\pi$ amplitudes can be pinned down, using well established Chiral Perturbation Theory techniques. The strong S--wave rescattering of the two final pions generates sizeable chiral loop corrections,…
We present a new phenomenological analysis of the inclusive rare decay $B \to X_s \ell^+\ell^-$. In particular, we present the first calculation of the NNLL contributions due to the leading two-loop matrix elements, evaluated for arbitrary…
The experimental determination of low energy pi K scattering phase shifts would assist in determining scattering lengths as well as low energy constants of chiral perturbation theory for which sum rules have been constructed. The FOCUS…
We investigate the future determination of the CKM matrix using theoretically clean quantities, like $B(K^+\to\pi^+\nu\bar\nu)$, $B(K_L\to\pi^0\nu\bar\nu)$ or $\sin 2\beta$, $\sin 2\alpha$ as extracted from CP violation studies in $B$…
We present a comprehensive analysis of the contributions to K->pi nu nu decays not described by the leading dimension-six effective Hamiltonian. These include both dimension-eight four-fermion operators generated at the charm scale, and…
We revisit the the rare kaon decays $K\to \pi l^+l^-$ which are of interest specially due to the recent measurements of the charged kaon decay spectra. We compute the contribution of the 27-plet to the decay amplitudes in one loop SU(3)…
We update the profile of the CKM matrix. The apex (rhobar,etabar) of the Unitarity Triangle is given by means of a global fit. We propose to include therein sin2alpha from the CP-violating asymmetries in B0->rho+rho-, using isospin to…
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.…