Muon $g-2$ with $SU(2)_L$ multiplets

TL;DR

This paper introduces a minimal $SU(2)_L$ multiplet model that explains the muon $g-2$ anomaly through new fermions and scalars, with neutrino mass generated via type-II seesaw, and explores collider implications.

Contribution

It presents a novel $SU(2)_L$ multiplet framework that simultaneously addresses muon $g-2$ and neutrino masses without extra symmetries, including detailed numerical and collider analyses.

Findings

Model achieves sizable muon $g-2$ consistent with experimental data.

Neutrino masses generated via type-II seesaw with triplet Higgs.

Collider signatures explored for new multiplet particles.

Abstract

We propose a simple model to obtain sizable muon anomalous magnetic dipole moment (muon $g-2$) introducing several $SU(2)_L$ multiplet fields without any additional symmetries. The neutrino mass matrix is simply induced via type-II seesaw scenario in terms of $SU(2)_L$ triplet Higgs with $U(1)_Y$ hypercharge 1. In addition, we introduce an $SU(2)_L$ quartet vector fermion with $1/2$ hypercharge and scalar with $3/2$ hypercharge. The quartet fermion plays a crucial role in explaining muon $g-2$ causing the chiral flip inside a loop diagram with mixing between triplet and quartet scalar bosons via the standard model Higgs. We show numerical analysis and search for allowed region in our parameter space, and demonstrate the collider physics.