Non-perturbative effects in WIMP scattering off nuclei in the NMSSM

TL;DR

This paper investigates how non-perturbative effects in the NMSSM could enhance neutralino-nucleon interactions, potentially impacting dark matter detection experiments by considering eta(b) resonance mixing with the pseudoscalar Higgs.

Contribution

It introduces a novel mechanism involving eta(b) resonance mixing and non-perturbative effects to explain enhanced neutralino scattering in the NMSSM.

Findings

Non-perturbative effects may significantly increase neutralino-nucleon cross sections.

Eta(b) resonance mixing could influence dark matter direct detection signals.

Potential explanation for current discrepancies in dark matter search results.

Abstract

We explore a scenario in the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM) with both a light O(10) GeV neutralino and a CP-odd Higgs boson with significant coupling to down-type fermions, evading all current B physics, LEP and WMAP bounds. Motivated by a possible slight lepton universality breaking hinted in Upsilon decays, we consider the effect of the mixing of eta(b) resonances with the pseudoscalar Higgs on the spin-dependent scattering neutralino cross section off nucleons. We conclude that this mechanism could be relevant provided that non-perturbative effects enhance the effective eta(b)-nucleon coupling, taking over velocity/q^2 suppression factors, perhaps giving a new insight into the current controversial situation concerning direct search experiments of dark matter.