scholarly journals Two-component Dark Matter in the vectorlike hypercolor extension of the Standard Model

2019 ◽  
Vol 201 ◽  
pp. 09001 ◽  
Author(s):  
Vitaly Beylin ◽  
Maxim Bezuglov ◽  
Vladimir Kuksa

We consider a minimal vectorlike extension of the Standard Model that naturally contains two types of stable neutral particles. They can be interpreted as the Dark Matter candidates. Here, the SM is supplemented by a new fermion (H-quark) sector that is in confilnement providing by the SU(2)HC gauge group. H-quarks interact with the SM particles via standard electroweak bosons. In analogy with the conventional QCD, H-quarks can form bound states, H-hadrons, that emerge in the σ− model framework. Along with the stable neutral H-pion, there is one more pseudo-goldstone (diquark) state, B0, which is stable and also can be a component of the DM. Mass splittings both for components of the H-pion triplet and for neutral H-pion and B0 have been calculated, it is shown that this splittings can be small. The relic abundance for this composition of the DM is analyzed as well as the DM particles scattering off nucleons. A feature of this scenario is that Dark Matter turns out to consist of particles which are close in mass but have different origin and interact differently with ordinary matter. So, the model predicts two-component structure of the DM together with some specifilc manifestations of it.

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Lucien Heurtier ◽  
Fei Huang ◽  
Tim M.P. Tait

Abstract In the framework where the strong coupling is dynamical, the QCD sector may confine at a much higher temperature than it would in the Standard Model, and the temperature-dependent mass of the QCD axion evolves in a non-trivial way. We find that, depending on the evolution of ΛQCD, the axion field may undergo multiple distinct phases of damping and oscillation leading generically to a suppression of its relic abundance. Such a suppression could therefore open up a wide range of parameter space, resurrecting in particular axion dark-matter models with a large Peccei-Quinn scale fa ≫ 1012 GeV, i.e., with a lighter mass than the standard QCD axion.


2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Cao H. Nam

AbstractWe propose a general flavor-independent extension of the Standard Model (SM) with the minimal particle content, based on the symmetry $$SU(3)_C\times SU(2)_L\times U(1)_{Y'}\times U(1)_X\times Z_2$$ S U ( 3 ) C × S U ( 2 ) L × U ( 1 ) Y ′ × U ( 1 ) X × Z 2 . In this scenario, the charge operator is identified in terms of the charges of two U(1) gauge symmetries. The light neutrino masses are generated via Type-I seesaw mechanism only with two heavy right-handed neutrinos acquiring their Majorana masses through the $$U(1)_{Y'}\times U(1)_X$$ U ( 1 ) Y ′ × U ( 1 ) X symmetry breaking. We study various experimental constraints on the parameters of the model and investigate the phenomenology of the right-handed neutrino dark matter (DM) candidate assigned a $$Z_2$$ Z 2 -odd parity. We find that the most important constraints are the observed DM relic abundance, the current LHC limits, and the ambiguity of the SM neutral gauge boson mass.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Michael J. Baker ◽  
Darius A. Faroughy ◽  
Sokratis Trifinopoulos

Abstract Motivated by UV explanations of the B-physics anomalies, we study a dark sector containing a Majorana dark matter candidate and a coloured coannihilation partner, connected to the Standard Model predominantly via a U1 vector leptoquark. A TeV scale U1 leptoquark, which couples mostly to third generation fermions, is the only successful single-mediator description of the B-physics anomalies. After calculating the dark matter relic surface, we focus on the most promising experimental avenue: LHC searches for the coloured coannihilation partner. We find that the coloured partner hadronizes and forms meson-like bound states leading to resonant signatures at colliders reminiscent of the quarkonia decay modes in the Standard Model. By recasting existing dilepton and monojet searches we exclude coannihilation partner masses less than 280 GeV and 400 GeV, respectively. Since other existing collider searches do not significantly probe the parameter space, we propose a new dedicated search strategy for pair production of the coloured partner decaying into bbττ final states and dark matter particles. This search is expected to probe the model up to dark matter masses around 600 GeV with current luminosity.


1992 ◽  
Vol 07 (09) ◽  
pp. 733-747 ◽  
Author(s):  
A. BOTTINO ◽  
V. DE ALFARO ◽  
N. FORNENGO ◽  
A. MORALES ◽  
J. PUIMEDÓN ◽  
...  

Direct search for neutralino dark matter is analyzed in the framework of the minimal supersymmetric extension of the standard model, using a realistic evaluation of the neutralino relic abundance which also includes radiative corrections to the Higgs masses. Relevance of the present (Ge detectors) experimental data to set constraints on the parameters of the model is discussed and expectations for future experiments which involve neutralino-nucleus coherent processes are investigated. These results are compared to those obtained in a previous paper from indirect search data. In the present analysis particular attention is paid to the theoretical uncertainties due to the different estimates of the Higgs-nucleon coupling strength.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Raffaele Tito D’Agnolo ◽  
Di Liu ◽  
Joshua T. Ruderman ◽  
Po-Jen Wang

Abstract We present kinematically forbidden dark matter annihilations into Standard Model leptons. This mechanism precisely selects the dark matter mass that gives the observed relic abundance. This is qualitatively different from existing models of thermal dark matter, where fixing the relic density typically leaves open orders of magnitude of viable dark matter masses. Forbidden annihilations require the dark matter to be close in mass to the particles that dominate its annihilation rate. We show examples where the dark matter mass is close to the muon mass, the tau mass, or the average of the tau and muon masses. We find that most of the relevant parameter space can be covered by the next generation of proposed beam-dump experiments and future high-luminosity electron positron colliders. Forbidden dark matter predicts large couplings to the Standard Model that can explain the observed value of (g − 2)μ.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Cédric Delaunay ◽  
Teng Ma ◽  
Yotam Soreq

Abstract We consider models of decaying spin-1 dark matter whose dominant coupling to the standard model sector is through a dark-Higgs Yukawa portal connecting a TeV-scale vector-like lepton to the standard model (right-handed) electron. Below the electron-positron threshold, dark matter has very slow, loop-suppressed decays to photons and (electron) neutrinos, and is stable on cosmological time-scale for sufficiently small gauge coupling values. Its relic abundance is set by in-equilibrium dark lepton decays, through the freeze-in mechanism. We show that this model accommodates the observed dark matter abundance for natural values of its parameters and a dark matter mass in the ∼ 5 keV to 1 MeV range, while evading constraints from direct detection, indirect detection, stellar cooling and cosmology. We also consider the possibility of a nonzero gauge kinetic mixing with the standard model hypercharge field, which is found to yield a mild impact on the model’s phenomenology.


2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Jérôme Claude ◽  
Stephen Godfrey

AbstractWe explore regions of parameter space that give rise to suppressed direct detection cross sections in a simple model of scalar dark matter with a scalar portal that mixes with the standard model Higgs. We found that even this simple model allows considerable room in the parameter space that has not been excluded by direct detection limits. A number of effects leading to this result have been previously noted. Our main new result explores interference effects between different contributions to DM annihilation when the DM mass is larger than the scalar portal mass. New annihilation channels open up and the parameters of the model need to compensate to give the correct DM relic abundance, resulting in smaller direct detection cross sections. We find that even in a very simple model of DM there are still sizeable regions of parameter space that are not ruled out by experiment.


2011 ◽  
Vol 2011 ◽  
pp. 1-34 ◽  
Author(s):  
Siavosh R. Behbahani ◽  
Martin Jankowiak ◽  
Tomas Rube ◽  
Jay G. Wacker

Theories of dark matter that support bound states are an intriguing possibility for the identity of the missing mass of the Universe. This article proposes a class of models of supersymmetric composite dark matter where the interactions with the Standard Model communicate supersymmetry breaking to the dark sector. In these models, supersymmetry breaking can be treated as a perturbation on the spectrum of bound states. Using a general formalism, the spectrum with leading supersymmetry effects is computed without specifying the details of the binding dynamics. The interactions of the composite states with the Standard Model are computed, and several benchmark models are described. General features of nonrelativistic supersymmetric bound states are emphasized.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Nicolás Bernal ◽  
Andrea Donini ◽  
Miguel G. Folgado ◽  
Nuria Rius

Abstract We study the possibility that Dark Matter (DM) is made of Feebly Interacting Massive Particles (FIMP) interacting just gravitationally with the Standard Model particles in the framework of a Clockwork/Linear Dilaton (CW/LD) model. We restrict here to the case in which the DM particles are scalar fields. This paper extends our previous study of FIMP’s in Randall-Sundrum (RS) warped extra-dimensions. As it was the case in the RS scenario, also in the CW/LD model we find a significant region of the parameter space in which the observed DM relic abundance can be reproduced with scalar DM mass in the MeV range, with a reheating temperature varying from 10 GeV to 109 GeV. We comment on the similarities of the results in both extra-dimensional models.


2015 ◽  
Vol 30 (03) ◽  
pp. 1550018 ◽  
Author(s):  
Sean Fraser ◽  
Ernest Ma ◽  
Mohammadreza Zakeri

Models of fermion and scalar dark matter abound. Here we consider instead vector dark matter, from an SU(2)N extension of the standard model. It has a number of interesting properties, including a possible implementation of the inverse seesaw mechanism for neutrino mass. The annihilation of dark matter for calculating its relic abundance in this model is not dominated by its cross-section to standard-model particles, but rather to other new particles which are in thermal equilibrium with those of the standard model.


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