Speaker
Description
Non-perturbative determinations of renormalization coefficients are an integral part of the continuum limit of lattice calculations. We explore an alternative strategy of determining the renormalization constants of the effective electroweak Hamiltonian. The method 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 renormalization conditions lead to relations between gauge-invariant off-shell two-point functions in coordinate space. As a simplified example, I will present the aforementioned strategy in the setting of twisted mass fermions to determine the renormalization constant of the axial current, including numerical results. The extension to 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 of the tau decay rate, which is discussed by Erik Bäske in this workshop.