NMHDECAY 2.0: An updated program for Sparticle masses, Higgs masses, couplings and decay widths in the NMSSM

TL;DR

NMHDECAY 2.0 addresses the need for precise NMSSM spectroscopy and decay predictions by extending the code to compute Higgs and sparticle masses, couplings, and decay widths with enhanced radiative corrections. It introduces Higgs decays into squarks and sleptons, computes the full sparticle spectrum, and links to NMSSM-compatible MicrOMEGAs to evaluate the dark matter relic density, while also providing a leading-order calculation of BR$(b \to s \gamma)$. The package includes comprehensive LEP/Tevatron constraint checks, enabling parameter-space testing beyond the MSSM limit, and offers SLHA-compatible input/output along with a scan mode for systematic exploration. The 2.1 update adds RG evolution up to the GUT scale, improving consistency checks on high-scale behavior, and the authors discuss future improvements to higher-order corrections and additional low-energy observables, underscoring the practical impact for NMSSM phenomenology and experimental planning.

Abstract

We describe the the improved properties of the NMHDECAY program, that is designed to compute Higgs and sparticle masses and Higgs decay widths in the NMSSM. In the version 2.0, Higgs decays into squarks and sleptons are included, accompagnied by a calculation of the squark, gluino and slepton spectrum and tests against constraints from LEP and the Tevatron. Further radiative corrections are included in the Higgs mass calculation. A link to MicrOMEGAs allows to compute the dark matter relic density, and a rough (lowest order) calculation of the BR(s -> b gamma) is performed.