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Chiral Lagrangian parameters for scalar and pseudoscalar mesons

TLDR
In this article, the results of a high-statistics study of scalar and pseudoscalar meson propagators in quenched lattice QCD are presented.
Abstract
The results of a high-statistics study of scalar and pseudoscalar meson propagators in quenched lattice QCD are presented. For two values of lattice spacing, $\ensuremath{\beta}=5.7(a\ensuremath{\approx}.18\mathrm{fm})$ and 5.9 $(a\ensuremath{\approx}.12\mathrm{fm}),$ we probe the light quark mass region using clover improved Wilson fermions with the modified quenched approximation pole-shifting ansatz to treat the exceptional configuration problem. The quenched chiral loop parameters ${m}_{0}$ and ${\ensuremath{\alpha}}_{\ensuremath{\Phi}}$ are determined from a study of the pseudoscalar hairpin correlator. From a global fit to the meson correlators, estimates are obtained for the relevant chiral Lagrangian parameters, including the Leutwyler parameters ${L}_{5}$ and ${L}_{8}.$ Using the parameters obtained from the singlet and nonsinglet pseudoscalar correlators, the quenched chiral loop (QCL) effect in the nonsinglet scalar meson correlator is studied. By removing this QCL effect from the lattice correlator, we obtain the mass and decay constant of the ground state scalar, isovector meson ${a}_{0}.$

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Journal ArticleDOI

The K→π vector form factor at zero momentum transfer on the lattice

TL;DR: In this article, a quenched lattice study of the form factors f + ( q 2 ) and f 0 (q 2 ) of the matrix elements 〈 π | s ¯ γ μ u | K 〉 is presented, which is necessary to extract | V u s | from K l 3 decays.
Journal ArticleDOI

Low-energy couplings of QCD from current correlators near the chiral limit

TL;DR: In this paper, a new numerical procedure was proposed to compute fermionic correlation functions at very small quark masses, where large statistical fluctuations, due to the presence of local ''bumps'' in the wave functions associated with the low-lying eigenmodes of the Dirac operator, are reduced by an exact low-mode averaging.
Journal ArticleDOI

Order p^6 chiral couplings from the scalar K Pi form factor

TL;DR: In this paper, the slope and curvature of the scalar Kπ form factor at zero momentum transfer were estimated using a coupled channel dispersion relation analysis (CPDR) and the result was in perfect agreement with a previous estimate by Leutwyler and Roos.

A Method for Simulating Chiral Fermions on the Lattice Submitted to Physics Letters B

TL;DR: In this article, a lattice theory of massive interacting fermions in 2n + 1 dimensions was used to simulate the behaviour of massless chiral fermion in 2 n dimensions if the mass has a step function shape in the extra dimension.
Journal ArticleDOI

Phase separation in a lattice model of a superconductor with pair hopping

TL;DR: Investigation of the extended Hubbard model with pair hopping in the atomic limit for arbitrary electron density and chemical potential shows that, depending on the values of interaction parameters, the system can exhibit not only the homogeneous phases, superconducting and nonordered states, but also the phase separated states.
References
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Journal ArticleDOI

Chiral Perturbation Theory: Expansions in the Mass of the Strange Quark

TL;DR: In this paper, the authors construct the generating functional of U(3)×U(3), which allows them to calculate the Green functions up to and including terms of order p4 (at fixed radio m quark p 2 ) in terms of a few coupling constants which chiral symmetry leaves undetermined.
Journal ArticleDOI

A Method for simulating chiral fermions on the lattice

TL;DR: In this article, a lattice theory of massive interacting fermions in 2 n + 1 dimensions was used to simulate the behavior of massless chiral fermion in 2n dimensions if the mass has a step function shape in the extra dimension.
Journal ArticleDOI

Viability of lattice perturbation theory.

TL;DR: It is shown that the apparent failure of QCD lattice perturbation theory to account for Monte Carlo measurements of perturbative quantities results from choosing the bare lattice coupling constant as the expansion parameter, and a new prescription for designing lattice operators that are more continuumlike than conventional operators is suggested.
Journal ArticleDOI

A construction of lattice chiral gauge theories

TL;DR: In this article, path integration over Euclidean chiral fermions is replaced by the quantum mechanics of an auxiliary system of non-interacting Fermions, avoiding the no-go theorem.
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