scholarly journals Reconstructing effective Lagrangians embedding residual family symmetries

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Jordan Bernigaud ◽  
Ivo de Medeiros Varzielas ◽  
Jim Talbert
Keyword(s):  
Finite Groups ◽  
Low Energy ◽  
Beyond The Standard Model ◽  
Top Down ◽  
Family Symmetry ◽  
Bottom Up ◽  
Effective Lagrangian ◽  
Mass Matrices ◽  
The Standard Model ◽  
Bsm Physics

AbstractWe consider effective Lagrangians which, after electroweak- and family-symmetry breaking, yield fermionic mass matrices and/or other flavoured couplings exhibiting residual family symmetries (RFS). Thinking from the bottom up, these RFS intimately link ultraviolet (UV) Beyond-the-Standard Model (BSM) physics to infrared flavour phenomenology without direct reference to any (potentially unfalsifiable) UV dynamics. While this discussion is typically performed at the level of RFS group generators and the UV flavour groups they can close, we now also focus on the RFS-implied shape of the low-energy mass/coupling matrices. We then show how this information can be used to algorithmically guide the reconstruction of an effective Lagrangian, thereby forming top-down models realizing the typical bottom-up phenomenological conclusions. As a first application we take results from scans of finite groups capable of controlling (through their RFS) CKM or PMNS mixing within the SM alone. We then extend this to recently studied scenarios where RFS also control special patterns of leptoquark couplings, thus providing proof-in-principle completions for such ‘Simplified Models of Flavourful Leptoquarks.’

scholarly journals Higgs and BSM Physics at the Future Muon Collider

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 851
Author(s):  
Roberto Franceschini ◽  
Mario Greco
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Recent Work ◽  
Low Energy ◽  
Beyond The Standard Model ◽  
Electroweak Symmetry ◽  
The Standard Model ◽  
Muon Collider ◽  
Bsm Physics ◽  
Muon Colliders

We describe recent work on the physics of the Higgs boson and breaking of the electroweak symmetry at future muon colliders. Starting from the low-energy muon collider at the Higgs boson pole we extend our discussion to the multi-TeV muon collider and outline the physics case for such machines about the properties of the Higgs boson and physics beyond the Standard Model that can be possibly discovered.

Removing the conspiracy of BSM physics and BSM cosmology

2019 ◽  
Vol 28 (13) ◽  
pp. 1941012 ◽  
Author(s):  
Maxim Yu. Khlopov
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Elementary Particles ◽  
Physical Basis ◽  
Particle Model ◽  
Beyond The Standard Model ◽  
Cosmological Scenario ◽  
The Standard Model ◽  
Modern Cosmology ◽  
Bsm Physics

The standard model (SM) of elementary particles finds no contradictions in the experimental data, but appeals to extensions for solutions of its internal problems and physical basis of the modern cosmology. The latter is based on inflationary models with baryosynthesis and dark matter/energy that involves Physics beyond the standard model (BSM) of elementary particles. However, studies of the BSM physical basis of the modern cosmology inevitably reveals additional particle model-dependent cosmological consequences that go beyond the modern standard cosmological model. The mutual relationship of the BSM particle physics basis of the modern cosmology and the nontrivial features of the corresponding cosmological scenario are the subject of this paper.

TECHNIDILATON OR HIGGS?

1993 ◽  
Vol 08 (03) ◽  
pp. 275-283 ◽  
Author(s):  
EDI HALYO
Keyword(s):  
Standard Model ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Higgs Bosons ◽  
Low Energy ◽  
Gauge Bosons ◽  
Effective Lagrangian ◽  
The Standard Model

Interactions of the technidilaton with fermions and gauge bosons are obtained by constructing a low energy effective Lagrangian and using the fact that the technidilaton couples to the trace of the energy-momentum tensor Θµµ. Technidilaton’s interactions are compared with those of the Higgs bosons of the Standard Model with one or two scalar doublets.

scholarly journals THE EFFECT OF ELECTROMAGNETIC PROPERTIES OF NEUTRINOS ON THE PHOTON–NEUTRINO DECOUPLING TEMPERATURE

2012 ◽  
Vol 27 (32) ◽  
pp. 1250187
Author(s):  
S. C. İNAN ◽  
M. KÖKSAL
Keyword(s):  
Lagrangian Model ◽  
Electromagnetic Properties ◽  
Beyond The Standard Model ◽  
Ultrahigh Energy ◽  
Qcd Phase Transition ◽  
Effective Lagrangian ◽  
Independent Analysis ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact

We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultrahigh energy cosmic neutrinos for the [Formula: see text] process. For this process, photon–neutrino decoupling temperature is calculated via effective Lagrangian model beyond the standard model. We find that photon–neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.

scholarly journals From old symmetries to new symmetries: Quarks, leptons and B-L

2014 ◽  
Vol 29 (29) ◽  
pp. 1430066 ◽  
Author(s):  
Rabindra N. Mohapatra
Keyword(s):  
Standard Model ◽  
Weak Interactions ◽  
Low Energy ◽  
Neutrino Masses ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Recent Developments

The Baryon–Lepton difference (B-L) is increasingly emerging as a possible new symmetry of the weak interactions of quarks and leptons as a way to understand the small neutrino masses. There is the possibility that current and future searches at colliders and in low energy rare processes may provide evidence for this symmetry. This paper provides a brief overview of the early developments that led to B-L as a possible symmetry beyond the standard model, and also discusses some recent developments.

scholarly journals DETERMINING αs FROM MEASUREMENTS AT Z: HOW NATURE PROMPTS US ABOUT NEW PHYSICS

1995 ◽  
Vol 10 (07) ◽  
pp. 605-613 ◽  
Author(s):  
M. SHIFMAN
Keyword(s):  
Standard Model ◽  
New Physics ◽  
Low Energy ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Standard Deviations ◽  
The One

The value of αs (Mz) emerging from the so-called global fits based mainly on the data at the Z peak (and assuming the standard model) is three standard deviations higher than the one stemming from the low-energy phenomenology. The corresponding value of Λ QCD is very large, ~500 MeV, and is incompatible with crucial features of QCD. If persists, the discrepancy should be interpreted as due to contributions to the Z-quark-antiquark vertices which go beyond the standard model.

RENORMALIZABILITY AND SEARCHING FOR THE ABELIAN Z′ BOSON IN FOUR-FERMION PROCESSES

2001 ◽  
Vol 16 (02) ◽  
pp. 179-188 ◽  
Author(s):  
A. V. GULOV ◽  
V. V. SKALOZUB
Keyword(s):  
Scalar Field ◽  
Z Boson ◽  
Axial Vector ◽  
Scalar Fields ◽  
Low Energy ◽  
Strongly Correlated ◽  
Absolute Value ◽  
Effective Lagrangian ◽  
The Standard Model ◽  
Model Independent

A model independent search for Abelian Z′ gauge boson in four-fermion processes is analyzed. It is based on a low energy effective Lagrangian parametrizing the Z′ interactions with the fermion and scalar fields of the Standard Model. These parameters are related due to the requirement of renormalizability (gauge invariance). It is found that the absolute value of the Z′ coupling to the axial-vector currents is the same for all fermions and it is strongly correlated with the Z′ coupling to the scalar field. On the base of these relations the dependences between the parameters of the effective Lagrangian constructed from dimension-six operators are derived.

scholarly journals Strongly interacting dynamics beyond the standard model on a space–time lattice

2010 ◽  
Vol 368 (1924) ◽  
pp. 3657-3670 ◽  
Author(s):  
Biagio Lucini
Keyword(s):  
Standard Model ◽  
Finite Size ◽  
Higgs Sector ◽  
Chiral Condensate ◽  
Space Time ◽  
Low Energy ◽  
Beyond The Standard Model ◽  
Fundamental Theory ◽  
Strongly Interacting ◽  
The Standard Model

Strong theoretical arguments suggest that the Higgs sector of the standard model of electroweak interactions is an effective low-energy theory, with a more fundamental theory expected to emerge at an energy scale of the order of a teraelectronvolt. One possibility is that the more fundamental theory is strongly interacting and the Higgs sector is given by the low-energy dynamics of the underlying theory. I review recent works aimed at determining observable quantities by numerical simulations of strongly interacting theories proposed in the literature to explain the electroweak symmetry-breaking mechanism. These investigations are based on Monte Carlo simulations of the theory formulated on a space–time lattice. I focus on the so-called minimal walking technicolour scenario, an SU(2) gauge theory with two flavours of fermions in the adjoint representation. The emerging picture is that this theory has an infrared fixed point that dominates the large-distance physics. I shall discuss the first numerical determinations of quantities of phenomenological interest for this theory and analyse future directions of quantitative studies of strongly interacting theories beyond the standard model with lattice techniques. In particular, I report on a finite size scaling determination of the chiral condensate anomalous dimension γ , for which 0.05≤ γ ≤0.25.

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