Coscattering/coannihilation dark matter in a fraternal twin Higgs model

Abstract

Dark matter candidates arise naturally in many models that address the hierarchy problem. In the fraternal twin Higgs model which could explain the absence of the new physics signals at the Large Hadron Collider (LHC), there are several viable dark matter candidates. In this paper we study the twin neutrino in the mass range ∼ 0.1-10 GeV as the dark matter. The thermal relic density is determined by the interplay of several annihilation and scattering processes between the twin neutrino, twin tau, and twin photon, depending on the order of the freeze-out temperatures of these processes. Besides the common coannihilation scenario where the relic density is controlled by the twin tau annihilation, it can realize the recently discovered coscattering phase if the scattering of the twin neutrino into the twin tau freezes out earlier than the twin tau annihilation. We also provide a method to calculate the thermal relic density in the intermediate regime where both coannihilation and coscattering processes contribute to the determination of the dark matter density. We show that the right amount of dark matter can be obtained in various scenarios in different regions of the parameter space. The current experimental constraints and future probes into the parameter space from direct detections, cosmological and astrophysical bounds, dark photon searches, and displaced decays at colliders, are discussed.

Insight into primordial magnetic fields from 21-cm line observation with EDGES experiment

“…Note that the EDGES result is difficult to explain by the standard scenario: The amplitude of the absorption trough is almost twice as large as the maximal value expected in the standard cosmology. However, instead of giving an explanation on this anomaly, several authors have already applied the EDGES result to constrain some models: the Hawking evaporation of small primordial black holes (PBHs) (Clark et al 2018), the emission from the accretion discs around large PBHs (Hektor et al 2018), the decaying (Clark et al 2018;Mitridate & Podo 2018) or annihilating dark matter (Cheng et al 2018;D'Amico et al 2018), warm dark matter (Safarzadeh et al 2018), primordial power spectrum (Yoshiura et al 2018) and so on.…”

Coscattering in next-to-minimal dark matter and split supersymmetry

“…Having the dark matter relic abundance dictated by the freeze-out of inelastic scattering processes rather than of coannihilations has been dubbed "coscattering" in [2]. This mechanism has since been explored in the context of several different models [6][7][8].…”

Composite twin dark matter

“…It has been shown that such cosmological tensions can be overcome [36][37][38][39] while continued analysis of cosmological data may reveal signatures of a twin-like structure [40][41][42][43][44]. Models of baryogenesis [45] as well as dark matter [46][47][48][49][50][51] have also been explored.…”