Smeared propagators for lattice hadron spectroscopy

Hadron spectroscopy from lattice QCD

I present recent developments in the lattice QCD calculations of the light hadron spectrum. Emphasis is placed on the limitation of the quenched approximation in reproducing the observed spectrum and indications that the discrepancy is reduced by introducing two flavors of light dynamical quarks.

Issues for the Lattice in Hadron Spectroscopy

The collective behaviour of gluons in the strong interaction regime of QCD is one of the black holes of the standard model. Lattice QCD and a range of QCD inspired models all suggest that the lightest glueballs occur in the 1-2 GeV region and that qq̄−gluon hybrids occur around 2 GeV in mass, yet, a quarter of a century after QCD was developed,their existence is not yet definitely established. T...

Bayesian Analysis of Many-Pole Fits of Hadron Propagators in Lattice QCD

A common procedure in Lattice QCD is to calculate a correlation function in a certain channel and then fit it as a sum of several exponentials [1– 4]. The parameters of the fits are estimated by minimizing χ. To find the errors, ideally the calculations should be repeated many times, but this is impractical. Usually the jacknife or the bootstrap is performed. Instead here we use Bayes’s theorem...

Hadron Spectroscopy

Excited hadrons from improved interpolating fields

The calculation of quark propagators for Ginsparg-Wilson-type Dirac operators is costly and thus limited to a few different sources. We present a new approach for determining spatially optimized operators for lattice spectroscopy of excited hadrons. Jacobi smeared quark sources with different widths are combined to construct hadron operators with different spatial wave functions. We study the R...