A tmQCD mixed-action approach to flavour physics

Abstract

We discuss a mixed-action approach in which sea quarks are regularised using non-perturbatively $\mathrm{O}(a)$ improved Wilson fermions, while a fully-twisted tmQCD action is used for valence quarks. In this setup, automatic $\mathrm{O}(a)$ improvement is preserved for valence observables, apart from small residual $\mathrm{O}(a)$ effects from the sea. A strategy for matching sea and valence is set up, and carried out for $N_{\mathrm{f}}=2+1$ CLS ensembles with open boundary conditions at several simulation points. The scaling of basic light-quark observables such as the pseudoscalar meson decay constant is studied, as well as the isospin splitting of pseudoscalar meson masses.

Comments: 11 pages, 5 figures, Proceedings of the 35th International Symposium on Lattice Field Theory (Lattice 2017), 18-24 June 2017, Granada, Spain