Related papers: Chiral low-energy constants from tau data
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…
A sum rule analysis of the hadronic tau-decay data can be used to determine the low-energy constants L10(mu) and C87(mu). These constants are QCD chiral-order parameters, which appear at order p^4 and p^6, respectively, in the chiral…
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…
Using the updated ALEPH V-A spectral function from tau decays, we determine the lowest spectral moments of the left-right correlator and extract dynamical information on order parameters of the QCD chiral symmetry breaking. Uncertainties…
We analyze the lowest spectral moments of the left-right two-point correlation function, using all known short-distance constraints and the recently updated ALEPH V-A spectral function from tau decays. This information is used to determine…
We use results of fits to the OPAL spectral data, obtained from non-strange hadronic \tau decays, to evaluate the difference between the vector and axial current correlators, \Pi_{V-A}(Q^2). The behavior of \Pi_{V-A}(Q^2) near euclidean…
We determined the NLO chiral low-energy constant $L_{10}$, and various combinations of NNLO chiral low-energy constants employing recently revised ALEPH results for the non-strange vector (V) and axial-vector (A) hadronic tau decay…
We determine the NLO chiral low-energy constant $L_{10}^r$, and combinations $C_{12}^r\pm C_{61}^r+C_{80}^r$, $C_{13}^r-C_{62}^r+C_{81}^r$, $C_{61}^r$, and $C_{87}^r$, of the NNLO chiral low-energy constants incorporating recently revised…
We present an analysis of the isospin-one V-A correlator based on our successful simultaneous description of the OPAL V and A non-strange tau spectral data. We discuss the values obtained for the Chiral Perturbation Theory low-energy…
Using a sequence of rational approximants and the large-Nc limit of QCD, we estimate the value of the low-energy constant C_87 which appears in the Lagrangian of Chiral Perturbation Theory at O(p^6).
A combination of finite energy sum rule techniques and Chiral Perturbation Theory (ChPT) is used in order to exploit recent ALEPH data on the non-strange tau vector (V) and axial-vector (A) spectral functions with respect to an experimental…
A new fit is done to obtain numerical values for the order $p^4$ low-energy-constants $L_i^r$ in Chiral Perturbation Theory. This includes both new data and new calculated observables. We take into account masses, decay constants,…
Chiral low-energy constants incorporate short-distance information from the dynamics involving heavier degrees of freedom not present in the chiral Lagrangian. We have studied the contribution of the lightest resonances to the chiral…
We analyze the spectral moments of the V-A two-point correlation function. Using all known short-distance constraints and the most recent experimental data from tau decays, we determine the lowest spectral moments, trying to assess the…
Experimental data from hadronic $\tau$ decays allow for a precision determination of the slope of the $I=1$ vacuum polarization at zero momentum. We use this information to provide a value for the next-to-next-to-leading order (NNLO)…
Using spectral data from non-strange and strange hadronic tau decays, flavor-breaking chiral sum rules involving the flavor ud and us current-current two-point functions are constructed and used to determine the SU(3) NNLO low-energy…
The decay constant of the $\eta$-meson in the framework of 'resummed' chiral perturbation theory is discussed. A theoretical prediction is compared to the available determinations. Compatibility of these determinations with the latest fits…
The low-energy $\pi\pi$ amplitude is computed explicitly to two-loop accuracy in the chiral expansion. It depends only on six independent (combinations of) low-energy constants which are not fixed by chiral symmetry. Four of these constants…
The hadronization structure of $\tau^- \to \eta \pi^- \pi^0 \nu_\tau$ decays is analyzed using Chiral Perturbation Theory with resonances, considering only the contribution of the lightest meson resonances at leading order in the $1/N_C$…
We propose analytic approximations of chiral SU(3) amplitudes for the extrapolation of lattice data to the physical meson masses. The method allows the determination of NNLO low-energy constants in a controllable fashion. We test the…