Extension of Standard Model in multi-spinor field formalism — Visible and dark sectors

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.

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.


Universe ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. 137
Author(s):  
Valerio Marra ◽  
Rogerio Rosenfeld ◽  
Riccardo Sturani

Despite the observational success of the standard model of cosmology, present-day observations do not tightly constrain the nature of dark matter and dark energy and modifications to the theory of general relativity. Here, we will discuss some of the ongoing and upcoming surveys that will revolutionize our understanding of the dark sector.


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.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Raghuveer Garani ◽  
Michele Redi ◽  
Andrea Tesi

Abstract We investigate the nightmare scenario of dark sectors that are made of non-abelian gauge theories with fermions, gravitationally coupled to the Standard Model (SM). While testing these scenarios is experimentally challenging, they are strongly motivated by the accidental stability of dark baryons and pions, that explain the cosmological stability of dark matter (DM). We study the production of these sectors which are minimally populated through gravitational freeze-in, leading to a dark sector temperature much lower than the SM, or through inflaton decay, or renormalizable interactions producing warmer DM. Despite having only gravitational couplings with the SM these scenarios turn out to be rather predictive depending roughly on three parameters: the dark sector temperature, the confinement scale and the dark pion mass. In particular, when the initial temperature is comparable to the SM one these scenarios are very constrained by structure formation, ∆Neff and limits on DM self-interactions. Dark sectors with same temperature or warmer than SM are typically excluded.


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.


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 (7) ◽  
Author(s):  
Masahiro Ibe ◽  
Shin Kobayashi ◽  
Keiichi Watanabe

Abstract The asymmetric dark matter (ADM) scenario solves the baryon-dark matter coincidence problem when the dark matter (DM) mass is of $$ \mathcal{O}(1) $$ O 1 GeV. Composite ADM models based on QCD-like strong dynamics are particularly motivated since the strong dynamics naturally provides the DM mass of $$ \mathcal{O}(1) $$ O 1 GeV and the large annihilation cross-section simultaneously. In those models, the sub-GeV dark photon often plays an essential role in transferring the excessive entropy in the dark sector into the visible sector, i.e., the Standard Model sector. This paper constructs a chiral composite ADM model where the U(1)D gauge symmetry is embedded into the chiral flavor symmetry. Due to the dynamical breaking of the chiral flavor symmetry, the model naturally provides the masses of the dark photon and the dark pions in the sub-GeV range, both of which play crucial roles for a successful ADM model.


2019 ◽  
Vol 212 ◽  
pp. 06004
Author(s):  
Minggang Zhao

Numerous astrophysical observations strongly suggest the existence of Dark Matter, which provides a hint of dark sector physics. There could exist many dark candidates predicted by theories BSM, such as dark photons and invisible things, that communicate with the Standard Model sector. The masses and decay modes of these particles are expected to be accessible at the BESIII experiment which is the only currently running tau-charm factory with the largest threshold charm samples and some other unique datasets. We have recently performed searches of dark photons and invisible things in several decay modes. Besides, FCNC processes, BNV/LNV processes are also investigated. This talk will summarize the recent results at BESIII on these searches for new physics BSM.


Author(s):  
W-Y. PAUCHY HWANG

We all know that in our family of the basic particles we have three generations but still don't know why - the so-called "family problem". On other hand, in view of the masses and oscillations, the neutrinos now present some basic difficulty in the Standard Model. In this note, I propose that on top of the SUc(3) × SU(2) × U(1) standard model there is an SUf(3) extension - a simple SUc(3) × SU(2) × U(1) × SUf(3) extended standard model - neutrino masses are obtained in a "renormalizable" way in the dark sector. On the dark matter side, the family gauge bosons (familons) are massive through the so-called "colored" Higgs mechanism while the remaining Higgs particles are also massive. As the bridge between the dark matter and the ordinary matter, the three neutrinos, the electron-like, muon-like, and tao-like neutrinos, form the basic family triplets. Hopefully all the couplings to the "visible" ordinary matter are through the neutrinos, explaining why dark matter (25 %) is more than visible matter (5 %) in our Universe.


2018 ◽  
Vol 168 ◽  
pp. 06007 ◽  
Author(s):  
Yasuhiro Yamamoto

The Atomiki anomaly can be interpreted as a new light vector boson. If such a new particle exists, it could be a mediator between the Standard Model sector and the dark sector including the dark matter. We discussed some simple effective models with these particles. In the models, the secluded dark matter models are good candidates to satisfy the thermal relic abundance. In particular, we found that the dark matter self-interaction can be large enough to solve the small scale structure puzzles if the dark matter is a fermion.


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