scholarly journals $$U(1)'$$ extensions of the $$\mu \nu \mathrm{SSM}$$

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
J. A. Aguilar-Saavedra ◽  
I. Lara ◽  
D. E. López-Fogliani ◽  
C. Muñoz

AbstractIn the $$\mu \nu $$ μ ν SSM, the presence of R-parity violating couplings involving right-handed (RH) neutrinos solves simultaneously the $$\mu $$ μ - and $$\nu $$ ν -problems. We explore extensions of the $$\mu \nu $$ μ ν SSM adding a $$U(1)'$$ U ( 1 ) ′ gauge group, which provides the RH neutrinos with a non-vanishing charge. In these models, dubbed U$$\mu \nu $$ μ ν SSM, the anomaly cancellation conditions impose the presence of exotic quarks in the spectrum that are vector-like under the standard model (SM) gauge group: either three pairs SU(2) quark singlets, or a pair of quark singlets together with a pair of quark doublets. Several singlets under the SM group can also be present, with the $$U(1)'$$ U ( 1 ) ′ charges making distinctions among them, and therefore allowing different types of couplings. Some of these singlets dynamically generate Majorana masses for the RH neutrinos, and others can be candidates for dark matter. The useful characteristics of models with $$U(1)'$$ U ( 1 ) ′ s are also present in U$$\mu \nu $$ μ ν SSM models: baryon-number-violating operators as well as explicit Majorana masses and $$\mu $$ μ terms are forbidden, and the domain wall problem is avoided. The phenomenology of U$$\mu \nu $$ μ ν SSM models is very rich. We analyze the experimental constraints on their parameter space, specially on the mass and mixing of the new $$Z'$$ Z ′ boson. In addition to the exotic quarks, which can hadronize inside the detector or decay producing SM particles, the U$$\mu \nu $$ μ ν SSM models can also have new signals such as decays of the $$Z'$$ Z ′ to sparticle pairs like right sneutrinos, charginos or neutralinos. Besides, $$Z'$$ Z ′ and Higgs mediated annihilations and interactions with the visible sector of WIMP dark matter particles, can also be present.

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Salvatore Bottaro ◽  
Marco Costa ◽  
Oleg Popov

Abstract The goal of this work is to find the simplest UV completion of Accidental Composite Dark Matter Models (ACDM) that can dynamically generate an asymmetry for the DM candidate, the lightest dark baryon (DCb), and simultaneously annihilate the symmetric component. In this framework the DCb is a bound state of a confining SU(N)DC gauge group, and can interact weakly with the visible sector. The constituents of the DCb can possess non-trivial charges under the Standard Model gauge group. The generation of asymmetry for such candidate is a two-flavor variation of the out-of-equilibrium decay of a heavy scalar, with mass Mϕ ≳ 1010 GeV. Below the scale of the scalars, the models recover accidental stability, or long-livedness, of the DM candidate. The symmetric component is annihilated by residual confined interactions provided that the mass of the DCb mDCb ≲ 75 TeV. We implement the mechanism of asymmetry generation, or a variation of it, in all the original ACDM models, managing to generate the correct asymmetry for DCb of masses in this range. For some of the models found, the stability of the DM candidate is not spoiled even considering generic GUT completions or asymmetry generation mechanisms in the visible sector.


2016 ◽  
Vol 31 (18) ◽  
pp. 1630027
Author(s):  
Ikuo S. Sogami

With multi-spinor fields which behave as triple-tensor products of the Dirac spinors, the Standard Model is extended so as to embrace three families of ordinary quarks and leptons in the visible sector and an additional family of exotic quarks and leptons in the dark sector of our Universe. Apart from the gauge and Higgs fields of the Standard Model symmetry G, new gauge and Higgs fields of a symmetry isomorphic to G are postulated to exist in the dark sector. It is the bi-quadratic interaction between visible and dark Higgs fields that opens a main portal to the dark sector. Breakdowns of the visible and dark electroweak symmetries result in the Higgs boson with mass 125 GeV and a new boson which can be related to the diphoton excess around 750 GeV. Subsequent to a common inflationary phase and a reheating period, the visible and dark sectors follow weakly-interacting paths of thermal histories. We propose scenarios for dark matter in which no dark nuclear reaction takes place. A candidate for the main component of the dark matter is a stable dark hadron with spin 3/2, and the upper limit of its mass is estimated to be 15.1 GeV/c2.


2018 ◽  
Vol 33 (10n11) ◽  
pp. 1830007 ◽  
Author(s):  
Agnieszka Ilnicka ◽  
Tania Robens ◽  
Tim Stefaniak

We give a brief overview of beyond the Standard Model (BSM) theories with an extended scalar sector and their phenomenological status in the light of recent experimental results. We discuss the relevant theoretical and experimental constraints, and show their impact on the allowed parameter space of two specific models: the real scalar singlet extension of the Standard Model (SM) and the Inert Doublet Model. We emphasize the importance of the LHC measurements, both the direct searches for additional scalar bosons, as well as the precise measurements of properties of the Higgs boson of mass 125 GeV. We show the complementarity of these measurements to electroweak and dark matter observables.


2012 ◽  
Vol 27 (21) ◽  
pp. 1250117 ◽  
Author(s):  
FAYYAZUDDIN

A model for electroweak unification of quarks and leptons, in a gauge group SUC(3) × SU(4) × UX(1) is constructed. The model requires, three generations of quarks and leptons which are replicas (mirror) of the standard quarks and leptons. The gauge group SU(4) × UX(1) is broken in such a way so as to reproduce standard model and to generate heavy masses for the vector bosons [Formula: see text], the leptoquarks and mirror fermions. It is shown lower limit on mass scale of mirror fermions is [Formula: see text], E- being the lightest mirror fermion coupled to Z boson. As the universe expands, the heavy matter is decoupled at an early stage of expansion and may be a source of dark matter. Leptoquarks in the model connect the standard model and mirror fermions. Baryon genesis in our universe implies antibaryon genesis in mirror universe.


2000 ◽  
Vol 15 (19) ◽  
pp. 1221-1225 ◽  
Author(s):  
G. B. TUPPER ◽  
R. J. LINDEBAUM ◽  
R. D. VIOLLIER

We examine the phenomenology of a low-energy extension of the Standard Model, based on the gauge group SU (3) ⊗ SU (2) ⊗ U (1)⊗ SO (3), with SO(3) operating in the shadow sector. This model offers vacuum νe → νs and νμ → ντ oscillations as the solution of the solar and atmospheric neutrino problems, and it provides a neutral heavy shadow lepton X that takes the role of a cold dark matter particle.


2016 ◽  
Vol 31 (27) ◽  
pp. 1650163 ◽  
Author(s):  
Ernest Ma ◽  
Nicholas Pollard ◽  
Oleg Popov ◽  
Mohammadreza Zakeri

We propose an extension of the Standard Model of quarks and leptons to include gauge B–L symmetry with an exotic array of neutral fermion singlets for anomaly cancellation. With the addition of suitable scalars also transforming under U(1)[Formula: see text], this becomes a model of radiative seesaw neutrino mass with possible multipartite dark matter. If leptoquark fermions are added, necessarily also transforming under U(1)[Formula: see text], the diphoton excess at 750 GeV, recently observed at the Large Hadron Collider, may also be explained.


2017 ◽  
Vol 32 (19) ◽  
pp. 1730018 ◽  
Author(s):  
Bartosz Fornal

A simple model is constructed based on the gauge symmetry [Formula: see text], with only the leptons transforming nontrivially under [Formula: see text]. The extended symmetry is broken down to the Standard Model gauge group at TeV-scale energies. We show that this model provides a mechanism for baryogenesis via leptogenesis in which the lepton number asymmetry is generated by [Formula: see text] instantons. The theory also contains a dark matter candidate — the [Formula: see text] partner of the right-handed neutrino.


2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Nobuchika Okada ◽  
Digesh Raut ◽  
Qaisar Shafi

AbstractTo address five fundamental shortcomings of the Standard Model (SM) of particle physics and cosmology, we propose a phenomenologically viable framework based on a $$U(1)_X \times U(1)_{PQ}$$ U ( 1 ) X × U ( 1 ) PQ extension of the SM, that we call “SMART U(1)$$_X$$ X ”. The $$U(1)_X$$ U ( 1 ) X gauge symmetry is a well-known generalization of the $$U(1)_{B-L}$$ U ( 1 ) B - L symmetry and $$U(1)_{PQ}$$ U ( 1 ) PQ is the global Peccei–Quinn (PQ) symmetry. Three right handed neutrinos are added to cancel $$U(1)_X$$ U ( 1 ) X related anomalies, and they play a crucial role in understanding the observed neutrino oscillations and explaining the observed baryon asymmetry in the universe via leptogenesis. Implementation of PQ symmetry helps resolve the strong CP problem and also provides axion as a compelling dark matter (DM) candidate. The $$U(1)_X$$ U ( 1 ) X gauge symmetry enables us to implement the inflection-point inflation scenario with $$H_{inf} \lesssim 2 \times 10^{7}$$ H inf ≲ 2 × 10 7  GeV, where $$H_{inf}$$ H inf is the value of Hubble parameter during inflation. This is crucial to overcome a potential axion domain wall problem as well as the axion isocurvature problem. The SMART U(1)$$_X$$ X framework can be successfully implemented in the presence of SU(5) grand unification, as we briefly show.


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.


1995 ◽  
Vol 364 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Enrique Alvarez ◽  
JoséM. Gracia-Bondía ◽  
C.P. Martín

Sign in / Sign up

Export Citation Format

Share Document