Light Dark Matter and the Electroweak Phase Transition in the NMSSM

TL;DR

This paper investigates how the NMSSM can accommodate light dark matter and a strong first-order electroweak phase transition, linking collider phenomenology with cosmological phase transition properties.

Contribution

It demonstrates that in the NMSSM near the Peccei-Quinn limit, light Higgs and dark matter particles can induce a strong first-order electroweak phase transition, connecting dark matter detection signals with early universe physics.

Findings

Light CP-even Higgs mass of a few GeV correlates with a strong first-order phase transition.

A direct detection cross-section of ~10^{-41} cm^2 is associated with a strong electroweak phase transition.

Light dark matter particles can satisfy relic density constraints and produce detectable signals.

Abstract

We analyze the stability of the vacuum and the electroweak phase transition in the NMSSM close to the Peccei-Quinn symmetry limit. This limit contains light Dark Matter (DM) particles with a mass significantly smaller than the weak scale and also light CP-even and CP-odd Higgs bosons. Such light particles lead to a consistent relic density and facilitate a large spin-independent direct DM detection cross section, that may accommodate the recently reported signatures at the DAMA and CoGeNT experiments. Studying the one-loop effective potential at finite temperature, we show that when the lightest CP-even Higgs mass is of the order of a few GeV, the electroweak phase transition tends to become first order and strong. The inverse relationship between the direct-detection cross-section and the lightest CP-even Higgs mass implies that a cross-section of the order of 10$^{-41}$ cm$^2$ is correlated with a strong first order phase transition.