Related papers: Approximating chiral SU(3) amplitudes
The definition and computation of the topological susceptibility in non-abelian gauge theories is complicated by the presence of non-integrable short-distance singularities. Recently, alternative representations of the susceptibility were…
We establish the framework for the comparison of $\pi K$ scattering amplitudes from SU(3) chiral perturbation theory with suitable dispersive representations which result from the combination of certain fixed-t dispersion relations with…
A chiral extrapolation of the light vector meson masses in the up, down and strange quark masses of QCD is presented. We apply an effective chiral Lagrangian based on the hadrogenesis conjecture to QCD lattice ensembles of PACS-CS,…
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.…
We analyze lattice data for octet baryon masses from the QCDSF collaboration employing manifestly covariant Baryon Chiral Perturbation Theory. It is shown that certain combinations of low-energy constants can be fixed more accurately than…
Simulations with 2+1 flavors of domain wall fermions provide us with the opportunity to compare the lattice data directly to the predictions of continuum chiral perturbation theory, up to corrections from the residual chiral symmetry…
A recent extension of a variationally optimized perturbation, combined with renormalization group properties in a straightforward way, can provide approximations to nonperturbative quantities such as the chiral symmetry breaking order…
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 present status of lattice calculations of f_B, B_B and SU(3) flavour breaking ratios such as f_Bs/f_B is reviewed. Particular attention is devoted to systematic uncertainties, such as those arising from the lack of simulation data for…
In the limit of infinitely heavy b-quarks we compute the SU(3)-breaking ratio xi of neutral B-meson mixing matrix elements. We also present results for the ratio of decay constants f_{B_s}/f_{B_d}. Our calculation employs…
A cluster algorithm is constructed and applied to study the chiral limit of the strongly coupled lattice Schwinger model involving staggered fermions. The algorithm is based on a novel loop representation of the model. Finite size scaling…
This review addresses the practical convergence of the ChPT series in the p-regime. In the SU(2) framework there is a number of new results, and improved estimates of \bar\ell_3 and \bar\ell_4 are available. In the SU(3) framework few new…
Baryon chiral perturbation theory as conventionally applied using dimensional regularization has a well-known problem with the convergence of the SU(3) chiral expansion. One can reformulate the theory equally rigorously using a…
We consider three-flavor QCD and perform a determination of the low-energy coupling $\hat{g}_\chi$ of SU(2) Heavy Meson Chiral Perturbation Theory. It is the $B^*B\pi$ coupling in the limit of static heavy and chiral light quarks and has…
I observe a rough volume-dependent scaling of the low eigenvalues of a chiral Dirac operator in lattice studies of SU(3) lattice gauge theory with two flavors of color sextet fermions, in its weak-coupling phase. The mean value of the ith…
A lattice calculation of the pseudoscalar decay constant of heavy-light mesons is reported. Results are obtained (in the quenched approximation) from lattices at $\beta=6.3$ through a procedure that interpolates between the static…
We have applied a new noncompact, gauge-invariant, Monte Carlo method to simulate the U(1), SU(2), and SU(3) gauge theories on 8^4 and 12^4 lattices. For U(1) the Creutz ratios of the Wilson loops agree with the exact results for beta > 0.5…
We study the chiral condensate $<\bar{\psi} \psi>$ for an SU(3) gauge theory with $N_f$ massless Dirac fermions in the fundamental representation when $N_f$ is increased from 2 to 6. For $N_f=2$, our lattice simulations of $<\bar{\psi} \psi…
We present results from numerical simulations of three different 3d four-fermion models that exhibit Z_2, U(1), and SU(2) x SU(2) chiral symmetries, respectively. We performed the simulations by using the hybrid Monte Carlo algorithm. We…
Due to improvements in computer performance and algorithms, the rapidly increasing cost for unquenched Wilson-type fermions with lighter quarks has been ameliorated and new simulations are now possible. Here we present results using two…