Axial vectors in DarkCast

TL;DR

This paper investigates new axial vector particles with couplings to standard model fermions, developing a data-driven method for decay rate estimation and providing constraints within a flexible framework incorporated into the DarkCast package.

Contribution

It introduces a generic framework for axial vectors with arbitrary couplings, utilizing data-driven decay estimates and making tools publicly available.

Findings

Derived experimental constraints for benchmark models.

Developed a data-driven method based on tau decay data.

Implemented calculations into the DarkCast package.

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.