Leptonic $g-2$ moments, CP phases and the Higgs boson mass constraint

TL;DR

This paper investigates how an extended MSSM model with a vector-like leptonic generation can explain the muon and electron g-2 anomalies while satisfying the Higgs mass constraint, highlighting the role of CP phases and heavy SUSY scales.

Contribution

It introduces a vector-like leptonic generation into MSSM to account for g-2 deviations and analyzes CP phase effects, showing compatibility with Higgs mass constraints and heavy SUSY scales.

Findings

Extended MSSM can explain g-2 anomalies with heavy SUSY.

CP phases significantly influence g-2 corrections.

Corrections remain non-zero even at PeV SUSY scales.

Abstract

Higgs boson mass measurement at $\sim 125$ GeV points to a high scale for SUSY specifically the scalar masses. If all the scalars are heavy, supersymmetric contribution to the leptonic $g-2$ moments will be significantly reduced. On the other hand the Brookhaven experiment indicates a 3sigma deviation from the standard model prediction. Here we analyze the leptonic $g-2$ moments in an extended MSSM model with inclusion of a vector like leptonic generation which brings in new sources of CP violation. In this work we consider the contributions to the leptonic $g-2$ moments arising from the exchange of charginos and neutralinos, sleptons and mirror sleptons, and from the exchange of $W$ and $Z$ bosons and of leptons and mirror leptons. We focus specifically on the $g-2$ moments for the muon and the electron where sensitive measurements exist. Here it is shown that one can get consistency with the current data on $g-2$ under the Higgs boson mass constraint. Dependence of the moments on CP phases from the extended sector are analyzed and it is shown that they are sensitively dependent on the phases from the new sector. It is shown that the corrections to the leptonic moments arising from the extended MSSM sector will be non-vanishing even if the SUSY scale extends into the PeV region.