2020/05/04 by Heitger, Jochen, Joswig, Fabian, Vladikas, Anastassios
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat)
paper · doi:10.48550/arxiv.2005.01352
We derive chiral Ward identities for lattice QCD with Wilson quarks and Nf ≥ 3 flavours, on small lattices with Schrödinger functional boundary conditions and vanishingly small quark masses. These identities relate the axial variation of the non-singlet pseudoscalar density to the scalar one, thus enabling the non-perturbative determination of the scale-independent ratio ZS/ZP of the renormalisation parameters of these operators. We obtain results for Nf=3 QCD with tree-level Symanzik-improved gluons and Wilson-Clover quarks, for bare gauge couplings which cover the typical range of large-volume Nf = 2+1 simulations with Wilson fermions at lattice spacings below 0.1 fm. The precision of our results varies from 0.3% to 1%, except for the coarsest lattice, where it is 2%. We discuss how the ZS/ZP ratio can be used in the non-perturbative calculations of O(a) improved renormalised quark masses.