Muon and Electron $(g-2)$ Anomalies with Non-Holomorphic Interactions in MSSM

TL;DR

This paper investigates how non-holomorphic interactions in the MSSM can simultaneously explain the muon and electron g-2 anomalies without requiring light electroweakinos or sleptons, by leveraging Yukawa threshold corrections and flavor-dependent effects.

Contribution

It introduces a novel MSSM framework with non-holomorphic terms that can account for both muon and electron g-2 anomalies simultaneously, avoiding the need for light superpartners.

Findings

Identified parameter space consistent with muon and electron g-2 within experimental bounds.

Demonstrated that Yukawa threshold corrections can enhance electron g-2 relative to muon g-2.

Showed compatibility with collider and dark matter constraints.

Abstract

The recent Fermilab muon $g-2$ result and the same for electron due to fine-structure constant measurement through ${}^{133}{\rm Cs}$ matter-wave interferometry are probed in relation to MSSM with non-holomorphic (NH) trilinear soft SUSY breaking terms, referred as NHSSM. Supersymmetric contributions to charged lepton $(g-2)_l$ can be enhanced via the new trilinear terms involving a wrong Higgs coupling with left and right-handed scalars. Unlike many MSSM based analyses, the model does not require a light electroweakino, or light sleptons, or unequal left and right slepton masses, or a very large higgsino mass parameter. The first part of the analysis involves $(g-2)_\mu$ constraint along with limits from Higgs mass, B-physics, collider data, direct detection of dark matter (DM) while focusing on a higgsino DM which is underabundant in nature. We then impose the constraint from electron $g-2$ where a large Yukawa threshold corrections (an outcome of NHSSM) and opposite signs of trilinear NH coefficients associated with $\mu$ and $e$ fields are used to satisfy the dual limits of $\Delta {a_\mu}$ and $\Delta {a_e}$ (where the latter comes with negative sign). Varying Yukawa threshold corrections further provide the necessary flavor-dependent enhancement of $\Delta {a_e}/m_e^2$ compared to that of $\Delta {a_\mu}/m_\mu^2$. A larger Yukawa threshold correction through $A^\prime_e$ for $y_e$ also takes away the direct proportionality of $a_e$ with respect to $\tan\beta$. With a finite intercept, $a_e$ becomes only an increasing function of $\tan\beta$. We identified the available parameter space in the two cases while also applying the ATLAS data on slepton pair production in the plane of slepton mass parameter and the mass of the lightest neutralino.