Constraints for scalars and pseudoscalars from $\left(g-2\right)_l$ and existing $e^+e^-$ colliders

Abstract

Scalars and pseudoscalars with masses in the MeV to GeV range are of interest in different extensions of the Standard Model. Such particles are often associated with dark matter, the strong CP problem and the $\left(g-2\right)_{\mu}$ anomaly. In this work we investigate limits for masses of such particles and their couplings to photons and leptons which can be derived from present and currently operating $e^+e^-$ collider experiments and recent $\left(g-2\right)_{l}$ measurements. Our work expands upon previous studies in several ways, demonstrating that the interplay of both couplings is a decisive factor in this type of analyses.