$M_W$, Dark Matter and $a_\mu$ in the NMSSM

TL;DR

This paper identifies parameter regions in the NMSSM that can simultaneously explain the W boson mass, muon g-2 anomaly, and dark matter relic density, highlighting the role of light electroweak sparticles and challenging detection prospects.

Contribution

It provides a comprehensive analysis of NMSSM parameter space that accounts for multiple experimental anomalies and observations, proposing benchmark points for future collider searches.

Findings

Light charginos, sleptons, and staus in the 100-800 GeV range can explain $M_W$ and $a_$ anomalies.

The LSP is singlino-like with mass below 140 GeV, potentially undetectable in future experiments.

A possible 95-98 GeV scalar signal aligns with mild excesses at LEP and CMS.

Abstract

We study regions in the parameter space of the NMSSM which are able to simultaneously explain the current measured values for the $W$ mass $M_W$ and the muon anomalous magnetic moment $a_\mu$, and provide a dark matter relic density consistent with the observations as well as constraints from detection experiments. The corresponding regions feature light charginos, sleptons and staus in the 100-800~GeV range, at least some of them with masses below 150~GeV such that the electroweakly-interacting SUSY particles generate sufficiently large contributions to $M_W$. The LSP is always singlino-like with a mass below 140~GeV, and could possibly remain invisible even at future detection experiments. Decays of electroweak sparticles proceed through cascades via staus and/or sleptons which makes their detection challenging. We propose benchmark points for future searches of such sparticles. The lightest CP-even scalar may have a mass in the 95-98~GeV range with, however, modest signal rates in view of the mild excesses reported in this range at LEP and by CMS at the LHC.