Status of $\mathbb{Z}_3$-NMSSM featuring a light bino-dominated LSP and a light singlet-like scalar under the LZ Experiment

Abstract

In the presence of a light singlet-like scalar, the bino-dominated dark matter (DM) candidate in the $\mathbb{Z}_3$-symmetric next-to-minimal supersymmetric standard model ($\mathbb{Z}_3$-NMSSM) exhibits notable deviations from its counterpart in the minimal supersymmetric standard model (MSSM), both in terms of its inherent properties and the mechanisms determining its relic abundance and detection prospects. Motivated by recent progress in experimental particle physics, this study systematically investigates the implications for the \( \mathbb{Z}_3 \)-NMSSM framework featuring a light bino-dominated DM particle and a light singlet-like scalar, ensuring theoretical consistency with empirical observations. Of particular significance are the latest results from the LUX-ZEPLIN (LZ) direct detection experiment, supersymmetry (SUSY) searches at the Large Hadron Collider (LHC), and precision measurements of the Muon g-2 anomaly at Fermilab, which collectively impose complementary constraints on the model's viable parameter space. A comprehensive parameter scan was conducted using the MultiNest algorithm, incorporating constraints from LZ-2022 data, LHC Higgs analyses, Muon g-2 measurements, and B-physics observables. The analysis reveals that current experimental limits -- particularly those on spin-independent (SI) and spin-dependent (SD) DM-nucleon scattering cross-sections and LHC constraints on electroweakinos -- severely restrict the model. Nevertheless, the framework remains capable of naturally accommodating the observed Z boson and standard model-like Higgs boson masses, accounting for the Muon g-2 anomaly, and inducing sizable corrections to the W boson mass. These results are distinctive to the NMSSM and emerge from the interplay of bino-dominated DM and singlino components, with essential contributions from higgsino.