Searching for dynamical fermion effects in UKQCD simulations

Computing resources available for simulations of lattice QCD are now powerful enough to investigate unquenching effects. UKQCD has embarked on a programme of studying these effects in the light hadron spectrum, static quark potential, glueball spectrum and topological sectors. The purpose of this paper is to investigate unquenching effects in the first of these areas. It is well known that the lattice cut-off is a function of both the gauge coupling, β, and dynamical quark mass, m (see e.g. [1]). For this reason, the philosophy we have chosen is to simulate at points along the “matched” trajectory in the (β, m) plane i.e. defined byfixed lattice spacing, a. This then disentangles lattice spacing artefacts with unquenching effects. Any variation of a physical quantity along this trajectory can sensibly be attributed to unquenching effects rather than lattice systematics. This work has been published in full in [2].