Speaker
Description
Non-perturbative determinations of renormalization and improvement coefficients are an integral part of the continuum limit of lattice calculations. We explore an alternative strategy that uses composite operators at positive flow time as probes together with finite axial Ward identities to resolve the mixing due to the breaking of chiral symmetry generated by Wilson-like fermions. The resulting conditions lead to relations between gauge-invariant off-shell two-point functions in coordinate space. I will present numerical results of the aforementioned strategy in the setting of twisted mass fermions. As a first simplified example, I discuss results regarding the extraction of the critical mass and \mathcal{O}(a)-improvement coefficients associated with the flow. Additionally, the extraction of the ratio of the renormalization constants of the non-singlet axial and vector current, as well as the non-singlet scalar and pseudo-scalar density, will be presented. The extension to the determination of the ratio of renormalization constants of the effective electroweak Hamiltonian will be discussed, with hopes to be used in an ongoing project to perform a measurement of the isospin-breaking corrections to the tau decay rate. This work is done with ETMC and RC* collaborations.