Related papers: Confronting hadronic tau decays with non-leptonic …
We analyze the sensitivity of hadronic tau decays to non-standard interactions within the model-independent framework of the Standard Model Effective Field Theory (SMEFT). Both exclusive and inclusive decays are studied, using the latest…
We study the $CP$-violating, $|\Delta S| =1$ parameter $\varepsilon '/\varepsilon$ by computing the hadronic matrix elements in the chiral quark model. We estimate the coefficients of the next-to-leading order terms in the chiral expansion…
We present new results of the tau hadronic spectral function analysis using data accumulated by the ALEPH detector at LEP during the years 1991-94. In addition to the vector spectral functions, the axial-vector spectral functions and,…
We present preliminary results on extractions of the chiral LECs L_10 and C_87 and constraints on the excited pseudoscalar state pi(1300) and pi(1800) decay constants obtained from an analysis of lattice data for the flavor ud light quark…
A number of old and new methods for computing $K\to\pi\pi$ amplitudes on the lattice are reevaluated. They all involve a non-perturbative determination of matching coefficients. I will show how problems related to operator mixing can be…
We study the volume dependence of the left-current correlator with non-degenerate quark masses to next-to-leading order in the chiral expansion. We consider three possible regimes: all quark masses are in the $\epsilon$-regime, all are in…
The role of the quark condensate for the low energy structure of QCD is discussed in some detail. In particular, the dependence of M_pi on m_u and m_d and the low energy theorems for the pi-pi scattering amplitude are reviewed. The new data…
We use the Vector formulation to evaluate vector and axial-vector exchange contributions to the O(p^4) weak Chiral Lagrangian. We recover in this framework the bulk of the contributions found previously by Ecker et al. in the antisymmetric…
The dispersive approach to QCD is applied to the study of the inclusive tau lepton hadronic decay. This approach provides the unified integral representations for the hadronic vacuum polarization function, related R function, and Adler…
We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently…
Rare kaon decays are an important testing ground of the electroweak flavor theory: They can provide new signals of CP-violating phenomena. The interplay of long-distance QCD effects in strangeness-changing transitions can be analyzed with…
Motivated by recent experimental advances in the corresponding measurements, non-leptonic hyperon decays are calculated, for the first time in a relativistic manner, in Chiral Perturbation Theory at next-to-leading order (NLO). On the one…
A number of recent determinations of $m_s$ using hadronic $\tau$ decay data involve inclusive analyses based on the so-called $(k,0)$ spectral weights. We show here that the OPE representations of the longitudinal contributions appearing in…
We explore the chiral aspects of extrapolation of observables calculated within lattice QCD, using the nucleon magnetic moments as an example. Our analysis shows that the biggest effects of chiral dynamics occur for quark masses…
These lectures are an introduction to the subject of chiral effective Lagrangians of the Standard Model and their applications, mostly in the sector of non--leptonic kaon decays, with special emphasis on CP--violation. The first lecture…
We review two lattice calculations involving charm hadrons: a determination of the vector and scalar form factors of the semileptonic $D \to \pi \ell \nu$ decays, which are relevant for the extraction of the CKM matrix element $\lvert…
The rare decays of a kaon into a pion and a charged lepton/antilepton pair proceed via a flavour changing neutral current and therefore may only be induced beyond tree level in the Standard Model. This natural suppression makes these decays…
Using recent precise hadronic tau-decay data on the V-A spectral function, and general properties of QCD such as analyticity, the operator product expansion and chiral perturbation theory, we get accurate values for the QCD chiral order…
It has been pointed out recently that a certain set of dimension-6 scalar $P$- and $CP$-violating light-quark-muon operators may be tested in $\eta$ and $\eta'$ decays to various final states involving $\mu^+\mu^-$ pairs, at a level not yet…
We study the unknown coupling constants that appear at order $p^4$ in the Chiral Perturbation Theory analysis of $K \to \pi \gamma^* \to \pi l^+ l^-$, $K^{+-} \to \pi^{+-} \gamma \gamma$ and $K \to \pi \pi \gamma$ decays. To that end, we…