LIght scalars with lepton number to solve the $(g-2)_e$ anomaly

TL;DR

This paper proposes light scalars with lepton number as a solution to the electron g-2 anomaly, highlighting their potential to address precision measurement discrepancies and discussing experimental constraints and future prospects.

Contribution

The study introduces a new class of light scalars with lepton number that can resolve the electron g-2 anomaly, analyzing their phenomenology and experimental constraints.

Findings

Light scalars with lepton number can reduce |a_e| to solve the g-2 anomaly.

A doubly-charged scalar below the GeV scale is favored by constraints.

Future experiments like MOLLER can further test these solutions.

Abstract

Scalars that carry lepton number can help mediate would-be lepton-number-violating processes, such as neutrinoless double $\beta$ decay or lepton-scattering-mediated nucleon-antinucleon conversion. Here we show that such new scalars can also solve the anomaly in precision determinations of the fine-structure constant $\alpha$ from atom interferometry and from the electron's anomalous magnetic moment, $a_e \equiv (g-2)_e/2$, by reducing $|a_e|$. Study of the phenomenological constraints on these solutions favor a doubly-charged scalar with mass below the GeV scale. Significant constraints arise from the measurement of the parity-violating asymmetry in M{\o}ller scattering, and we consider the implications of the next-generation MOLLER experiment at Jefferson Laboratory and of an improved $a_e$ measurement.