Electrophobic Scalar Boson and Muonic Puzzles

TL;DR

This paper proposes a new scalar boson to address the proton radius puzzle and muon g-2 discrepancy, constraining its properties through experimental data and exploring future research directions.

Contribution

It introduces a model-independent analysis of a scalar boson coupling to leptons and nucleons, identifying viable parameter regions to solve key muonic puzzles.

Findings

Scalar boson mass constrained between 100 keV and 100 MeV.

Two unexplored regions in coupling-mass parameter space identified.

Implications for future experiments and lepton coupling theories discussed.

Abstract

A new scalar boson which couples to the muon and proton can simultaneously solve the proton radius puzzle and the muon anomalous magnetic moment discrepancy. Using a variety of measurements, we constrain the mass of this scalar and its couplings to the electron, muon, neutron, and proton. Making no assumptions about the underlying model, these constraints and the requirement that it solve both problems limit the mass of the scalar to between about 100 keV and 100 MeV. We identify two unexplored regions in the coupling constant-mass plane. Potential future experiments and their implications for theories with mass-weighted lepton couplings are discussed.