English

Non-singlet vector current in lattice QCD: $\mathrm{O}(a)$-improvement from large volumes

High Energy Physics - Lattice 2025-10-09 v1

Abstract

In previous work, we determined the improvement coefficients cVc_\mathrm{V} and cV~c_{\tilde{\mathrm{V}}} required for the massless O(a)\mathrm{O}(a)-improvement of the local and point-split discretizations of the non-singlet vector current for Nf=3N_\mathrm{f}=3 non-perturbatively O(a)\mathrm{O}(a)-improved Wilson fermions and the L\"uscher-Weisz gauge action, using ensembles of large-volume configurations generated by the Coordinated Lattice Simulations (CLS) initiative. A new estimate for the mass-dependent improvement coefficient bˉAeff\bar{b}_{\mathrm{A}}^\mathrm{eff} has recently become available, differing from the one used in our earlier study, and on which our implementation via a massive axial Ward identity relied. Here, we update our analysis of the mass-independent vector improvement coefficients based on the new axial current improvement coefficient, and analyse additional ensembles with a different chiral trajectory in order to validate our results at two values of the bare coupling. We find that using the new estimate of bˉAeff\bar{b}_{\mathrm{A}}^\mathrm{eff} improves the consistency between the two chiral trajectories, as well as with a previous determination of the improvement coefficients directly in the massless limit on small volumes.

Keywords

Cite

@article{arxiv.2510.06869,
  title  = {Non-singlet vector current in lattice QCD: $\mathrm{O}(a)$-improvement from large volumes},
  author = {Tim Harris and Harvey B. Meyer},
  journal= {arXiv preprint arXiv:2510.06869},
  year   = {2025}
}

Comments

5 pages, 2 figures

R2 v1 2026-07-01T06:23:31.513Z