Gauge-invariant smearing and matrix correlators using Wilson fermions atβ=6.2

Excited hadrons on the lattice: Mesons

“…In [5,10] it was proposed, and tested on small lattices, to use Jacobi smeared quark sources of different widths to allow for nodes in the radial wavefunction. Other lattice efforts [11,12] have also seen the need of using spatially extended operators.…”

Light hadron spectrum and decay constants in quenched lattice QCD

“…Although there are advantages to using smeared sources and/or sinks to extract ground-state properties from 2-point functions [12], constraints imposed by other parts of the UKQCD programme did not allow us this option.…”

“…We use the parameters from this latter fit to fix m P and the matrix element 0|P |P . We find that this particular ratio of correlators gives the cleanest signal from which to extract f P [12]. We determine f V by fitting to…”

Excited baryons from the FLIC fermion action

“…1 we show the N and N * ( 1 2 − ) masses as a function of m 2 π for the new simulations with the FLIC action. For comparison, we also show results from earlier simulations with Wilson [6] and domain wall fermions (DWF) [4], and a nonperturbatively improved clover action [3] with different source smearing and volumes.…”

“…Another challenge is presented by the odd parity Λ * (1405), whose anomalously small mass has been interpreted as an indication of strong coupled channel effects, and a weak overlap with a three-valence quark state. While model studies have provided some understanding of the level orderings and mass splittings in the baryons spectrum, it is hoped that lattice QCD [1,2,3,4] will provide a definitive resolution of some of the outstanding issues.…”