Light dark matter in a minimal extension with two additional real singlets

Markos Maniatis

doi:10.1103/physrevd.103.015010

Abstract

The direct searches for heavy scalar dark matter with a mass of order 100 GeV are much more sensitive than for light dark matter of order 1 GeV. The question arises whether dark matter could be light and has escaped detection so far. We study a simple extension of the Standard Model with two additional real singlets. We show that this simple extension may provide the observed relic dark matter density, does neither disturb big-bang nucleosynthesis nor the cosmic microwave background radiation observations and fulfills the conditions of clumping behavior for different sizes of galaxies. The potential of one Standard Model-like Higgs-boson doublet and the two singlets gives rise to a changed Higgs phenomenology, in particular, an enhanced invisible Higgs-boson decay rate is expected, detectable by missing transversal momentum searches at the ATLAS and CMS experiments at CERN.

Highlights

It has been reported [1] that the NGC1052–DF2 galaxy with a stellar mass of approximately 2 × 108 solar masses has a rotational movement in accordance with its observed mass
From the explicit calculation of the cross section we find that the self-interacting cross section per dark matter (DM) mass drops orders of magnitude with increasing relative velocities
The lowest bounds in these experiments come from searches of dark matter particles with a mass of the order of 100 GeV

Summary

INTRODUCTION

It has been reported [1] that the NGC1052–DF2 galaxy with a stellar mass of approximately 2 × 108 solar masses has a rotational movement in accordance with its observed mass. The upper bounds for light scalar DM are orders of magnitudes less stringent than the bounds for heavy DM particles with masses of Oð100 GeVÞ Let us in this context recall that interactions of DM with SM particles can not be arbitrarily small: supposing that DM is produced dynamically in the evolution of the Universe, for decreasing annihilation cross sections of the DM particles to Standard Model particles, the annihilation processes become more and more rare in the evolution of the Universe and freeze out happens earlier—corresponding to a higher DM number density. We focus on the two-realscalar extension of the SM with one light DM candidate accompanied by a mediator

THE MINIMAL EXTENSION WITH TWO ADDITIONAL REAL SINGLETS

PHENOMENOLOGY OF DARK MATTER AND THE MEDIATOR

CONCLUSIONS