Excited states in staggered meson propagators

Contamination of Excited States in Quenched QCD Hadron Propagators

Quenched QCD hadron spectrum is calculated with Wilson’s quark action at β = 5.85 and 6.0 on a 24 × 54 lattice. We discuss the problem of whether we have extracted the mass of the ground state at these β’s without contamination of the excited states. We show that the masses of the first excited states turn out to be consistent with experiment when we are able to obtain the propagators up to the...

Meson-meson interactions and Regge propagators

By a reformulation of the loop expansion in the Resonance-Spectrum-Expansion amplitude for meson-meson scattering, in terms of s-channel exchange of families of propagator modes, we obtain a formalism which allows for a wider range of applications. The connection with the unitarized amplitudes employed in some chiral theories is discussed. We also define an alternative for the Regge spectra and...

Finite - size Scaling of Meson Propagators

Using quenched chiral perturbation theory we compute meson correlation functions at finite volume and fixed gauge field topology. We also present the corresponding analytical predictions for the unquenched theory at fixed gauge field topology. These results can be used to measure the low-energy parameters of the chiral Langrangian from lattice simulations in volumes much smaller than one pion C...

Scalar Meson Spectroscopy with Lattice Staggered Fermions

Quark correlations and gluon propagators in elastic vector meson production ∗

The exchange of two–gluons is the simplest realization of the pomeron in terms of the QCD degrees of freedom [1]. It was recently shown that the two–gluon exchange model can account for experimental data for the differential cross section of ρ and φ photoproduction up to a momentum transfer of −t . 6 GeV and −t . 3 GeV respectively [2,3], which is the largest momentum range available so far. On...