Di-Higgs and tri-Higgs boson signals of muon $g-2$ at a muon collider

TL;DR

This paper demonstrates that explanations of the muon g-2 anomaly involving new leptons predict large di-Higgs and tri-Higgs production rates at muon colliders, regardless of the specific model details.

Contribution

It provides model-independent predictions for Higgs pair and triplet production rates linked to muon g-2 explanations involving new leptons.

Findings

Cross sections are about 240 ab for μ+μ−→hh, independent of energy.

Cross sections are about 2.7 ab for μ+μ−→hhh at 1 TeV, increasing quadratically with energy.

Predictions extend to models with different lepton quantum numbers and two Higgs doublet models.

Abstract

We show that new physics explanations of the muon $g-2$ anomaly by the contributions of new leptons mediated by the standard model Higgs boson necessarily lead to large rates for $\mu^+ \mu^- \to hh$ and $\mu^+ \mu^- \to hhh$ irrespectively of details of the model or the scale of new physics. For new leptons with the same quantum numbers as the standard model leptons, cross sections are expected to be about 240 ab for $\mu^+ \mu^- \to hh$ independently of the center of mass energy, $\sqrt{s}$, and about 2.7 ab for $\mu^+ \mu^- \to hhh$ for $\sqrt{s} = 1$ TeV and growing quadratically with $\sqrt{s}$. Predictions for models featuring new leptons with different quantum numbers and for a type-II two Higgs doublet model, where additional Higgs bosons can contribute to muon $g-2$, are also presented.