In previous work, we determined the improvement coefficients cV and cV~ required for the massless O(a)-improvement of the local and point-split discretizations of the non-singlet vector current for Nf=3 non-perturbatively 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 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 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.
@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}
}