Axial vectors in DarkCast

Abstract

In this work, we explore new spin-1 states with axial couplings to the standard model fermions. We develop a data-driven method to estimate their hadronic decay rates based on data from $\tau$ decays and using SU(3)$_{\rm flavor}$ symmetry. We derive the current and future experimental constraints for several benchmark models. Our framework is generic and can be used for models with arbitrary vectorial and axial couplings to quarks. We have made our calculations publicly available by incorporating them into the DarkCast package, see https://gitlab.com/darkcast/releases.