Regular Article – Theoretical Physics
The renormalised improved vector current in three-flavour lattice QCD with Wilson quarks
Westfälische Wilhelms-Universität Münster, Institut für Theoretische Physik, Wilhelm-Klemm-Straße 9, 48149, Münster, Germany
Accepted: 8 March 2021
Published online: 23 March 2021
We present the results of a non-perturbative determination of the improvement coefficient and the renormalisation factor , which define the renormalised vector current in three-flavour improved lattice QCD with Wilson quarks and tree-level Symanzik-improved gauge action. In case of the improvement coefficient, we consider both lattice descriptions of the vector current, the local as well as the conserved (i.e., point-split) one. Our improvement and normalisation conditions are based on massive chiral Ward identities and numerically evaluated in the Schrödinger functional setup, which allows to eliminate finite quark mass effects in a controlled way. In order to ensure a smooth dependence of the renormalisation constant and improvement coefficients on the bare gauge coupling, our computation proceeds along a line of constant physics, covering the typical range of lattice spacings that is useful for phenomenological applications. Especially for the improvement coefficient of the local vector current, we report significant differences between the one-loop perturbative estimates and our non-perturbative results.
© The Author(s) 2021
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