scholarly journals ELECTROWEAK UNIFICATION OF QUARKS AND LEPTONS IN A GAUGE GROUP SUC(3) × SU(4) × UX(1)

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.

2017 ◽  
Vol 32 (15) ◽  
pp. 1740005 ◽  
Author(s):  
Wan-Zhe Feng ◽  
Pran Nath

A brief review is given of some recent works where baryogenesis and dark matter have a common origin within the U(1) extensions of the Standard Model (SM) and of the minimal supersymmetric Standard Model (MSSM). The models considered generate the desired baryon asymmetry and the dark matter to baryon ratio. In one model, all of the fundamental interactions do not violate lepton number, and the total [Formula: see text] in the Universe vanishes. In addition, one may also generate a normal hierarchy of neutrino masses and mixings in conformity with the current data. Specifically, one can accommodate [Formula: see text] consistent with the data from Daya Bay reactor neutrino experiment.


LEP data constrain severely many proposed extensions of the Standard Model. These include: massive neutrinos, which are now largely excluded as candidates for the dark matter of the Universe; supersymmetric particles, the lightest of which would still constitute detectable dark matter; technicolour, of which many favoured versions are now excluded by precision electroweak measurements; and grand unified theories, of which LEP data favour supersymmetric versions.


2018 ◽  
Vol 33 (02) ◽  
pp. 1830003 ◽  
Author(s):  
John Ellis

The most important discovery in particle physics in recent years was that of the Higgs boson, and much effort is continuing to measure its properties, which agree obstinately with the Standard Model, so far. However, there are many reasons to expect physics beyond the Standard Model, motivated by the stability of the electroweak vacuum, the existence of dark matter and the origin of the visible matter in the Universe, neutrino physics, the hierarchy of mass scales in physics, cosmological inflation and the need for a quantum theory for gravity. Most of these issues are being addressed by the experiments during Run 2 of the LHC, and supersymmetry could help resolve many of them. In addition to the prospects for the LHC, I also review briefly those for direct searches for dark matter and possible future colliders.


Author(s):  
A. L. DOS SANTOS ◽  
D. HADJIMICHEF

We investigate a double extension to the Standard Model (SM). A first extension introduces, via minimal coupling, a massive Z′ boson. This enlarged SM is coupled to a dark matter sector through the Stueckelberg mechanism by a A′ boson. However, the A′ boson does not interact directly with the SM fermions. In our study, we found that the A′ is a massless photon-like particle in dark sector. Constraints on the mass for Z′ and corrections to Z mass are obtained.


2018 ◽  
Vol 33 (32) ◽  
pp. 1850190 ◽  
Author(s):  
José Bordes ◽  
Hong-Mo Chan ◽  
Sheung Tsun Tsou

The framed standard model (FSM), constructed initially for explaining the existence of three fermion generations and the hierarchical mass and mixing patterns of quarks and leptons,[Formula: see text] suggests also a “hidden sector” of particles3 including some dark matter candidates. It predicts in addition a new vector boson [Formula: see text], with mass of order TeV, which mixes with the [Formula: see text] and [Formula: see text] of the standard model yielding deviations from the standard mixing scheme, all calculable in terms of a single unknown parameter [Formula: see text]. Given that standard mixing has been tested already to great accuracy by experiment, this could lead to contradictions, but it is shown here that for the three crucial and testable cases so far studied (i) [Formula: see text], (ii) [Formula: see text], (iii) [Formula: see text]), the deviations are all within the present stringent experimental bounds provided [Formula: see text] TeV, but should soon be detectable if experimental accuracy improves. This comes about because of some subtle cancellations, which might have a deeper reason that is not yet understood. By virtue of mixing, [Formula: see text] can be produced at the LHC and appear as a [Formula: see text] anomaly. If found, it will be of interest not only for its own sake but serve also as a window on to the “hidden sector” into which it will mostly decay, with dark matter candidates as most likely products.


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.


2004 ◽  
Vol 13 (07) ◽  
pp. 1335-1344
Author(s):  
JOSÉ A. de FREITAS PACHECO ◽  
S. PEIRANI

Evidences for the existence of dark matter in the Universe are briefly reviewed and, in particular, the nature of the galactic halo. Possible candidates, point-like or not, issued from extensions of the Standard Model or Supersymmetric theories are examined. Finally, direct and indirect searches for dark matter particles are summarized.


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.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Alexandre Carvunis ◽  
Diego Guadagnoli ◽  
Méril Reboud ◽  
Peter Stangl

Abstract We present a model of composite Dark Matter (DM), in which a new QCD-like confining “hypercolor” sector generates naturally stable hyperbaryons as DM candidates and at the same time provides mass to new weakly coupled gauge bosons H that serve as DM mediators, coupling the hyperbaryons to the Standard Model (SM) fermions. By an appropriate choice of the H gauge symmetry as a horizontal SU(2)h SM flavor symmetry, we show how the H gauge bosons can be identified with the horizontal gauge bosons recently put forward as an explanation for discrepancies in rare B-meson decays. We find that the mass scale of the H gauge bosons suggested by the DM phenomenology intriguingly agrees with the one needed to explain the rare B-decay discrepancies.


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