Light dark matter in the NMSSM: upper bounds on direct detection cross sections

TL;DR

This paper investigates the upper limits on direct detection cross sections for light dark matter particles in the NMSSM, considering experimental constraints and their implications for current detection experiments.

Contribution

It provides new upper bounds on dark matter-nucleon cross sections in the NMSSM for light LSPs, incorporating constraints from B-physics, LEP, and OPAL data.

Findings

Upper bounds on spin-independent cross section ~ 10^{-42} cm^{-2}

Upper bounds on spin-dependent cross section ~ 4×10^{-40} cm^{-2}

Bounds are below DAMA and CoGeNT regions but compatible with CDMS-II events.

Abstract

In the Next-to-Minimal Supersymmetric Standard Model, a bino-like LSP can be as light as a few GeV and satisfy WMAP constraints on the dark matter relic density in the presence of a light CP-odd Higgs scalar. We study upper bounds on the direct detection cross sections for such a light LSP in the mass range 2-20 GeV in the NMSSM, respecting all constraints from B-physics and LEP. The OPAL constraints on e^+ e^- -> \chi^0_1 \chi^0_i (i > 1) play an important role and are discussed in some detail. The resulting upper bounds on the spin-independent and spin-dependent nucleon cross sections are ~ 10^{-42} cm^{-2} and ~ 4\times 10^{-40} cm^{-2}, respectively. Hence the upper bound on the spin-independent cross section is below the DAMA and CoGeNT regions, but could be compatible with the two events observed by CDMS-II.