New physics for muon anomalous magnetic moment and its electroweak precision analysis

TL;DR

This paper explores new physics models with additional Yukawa interactions to explain the muon g-2 anomaly, analyzing their effects on electroweak precision observables and collider phenomenology.

Contribution

It introduces and compares two simple models for muon g-2 that incorporate new particles and Yukawa couplings, assessing their consistency with experimental data.

Findings

Models with internal fermion line chirality flips require smaller Yukawa couplings.

Both models can explain muon g-2 deviation within electroweak constraints.

Predictions include effects on Higgs decay and LHC particle searches.

Abstract

About 3 sigma deviation from the standard model prediction of muon anomalous magnetic moment (muon g-2) has been reported. We consider new physics beyond the standard model which has new Yukawa interactions with muon. We compute new contributions to muon g-2 and corrections to electroweak observables, and show the consistent region of parameter space. We find that in a simple model where the chirality flip of muon occurs only in the external muon line in one-loop muon g-2 diagrams, it is necessary to introduce the relatively large new Yukawa coupling and the electroweak scale new particles. On the other hand, in a model where the chirality flip can occur in the internal fermion line of one loop muon g-2 diagrams, we can obtain favorable g-2 contributions without large Yukawa coupling, and they are consistent with the precision electroweak observables. Finally, we discuss effects of new particles for muon g-2 on the Higgs boson decay h to 2 photons and direct productions of these particles at the LHC experiment.