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

TL;DR

This paper derives constraints on light scalar and pseudoscalar particles in the MeV to GeV range, using data from $e^+e^-$ colliders and $(g-2)_l$ measurements, highlighting the importance of their couplings to photons and leptons.

Contribution

It provides updated limits on such particles' masses and couplings, emphasizing the combined effect of photon and lepton interactions, expanding previous analyses.

Findings

Constraints on scalar and pseudoscalar masses and couplings derived.

Interplay of photon and lepton couplings is crucial in the analysis.

Current collider data and $(g-2)_l$ measurements set significant limits.

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.