Radiative mass generation in scale invariant systems with spontaneous symmetry breakdown

2005 ◽  
pp. 81-92
Author(s):  
R. Collina
Keyword(s):  
Scale Invariant ◽  
Mass Generation ◽  
Symmetry Breakdown ◽  
Spontaneous Symmetry Breakdown

scholarly journals CONFORMAL HIGGS, OR TECHNI-DILATON — COMPOSITE HIGGS NEAR CONFORMALITY

2010 ◽  
Vol 25 (27n28) ◽  
pp. 5128-5144 ◽  
Author(s):  
KOICHI YAMAWAKI
Keyword(s):  
Goldstone Boson ◽  
Gluon Condensate ◽  
Bound State ◽  
Fermion Mass ◽  
Scale Invariant ◽  
Mass Generation ◽  
Composite Higgs ◽  
Njl Model ◽  
Holographic Approach ◽  
Intrinsic Scale

In contrast to the folklore that Technicolor (TC) is a "Higgsless theory", we shall discuss existence of a composite Higgs boson, Techni-Dilaton (TD), a pseudo-Nambu-Goldstone boson of the scale invariance in the Scale-invariant/Walking/Conformal TC (SWC TC) which generates a large anomalous dimension γm ≃ 1 in a wide region from the dynamical mass [Formula: see text] of the techni-fermion all the way up to the intrinsic scale ΛTC of the SWC TC (analogue of ΛQCD), where ΛTC is taken typically as the scale of the Extended TC scale Λ ETC : Λ TC ≃ Λ ETC ~ 103 TeV (≫ m). All the techni-hadrons have mass on the same order [Formula: see text], which in SWC TC is extremely smaller than the intrinsic scale Λ TC ≃ Λ ETC , in sharp contrast to QCD where both are of the same order. The mass of TD arises from the non-perturbative scale anomaly associated with the techni-fermion mass generation and is typically 500-600 GeV, even smaller than other techni-hadrons of the same order of [Formula: see text], in another contrast to QCD which is believed to have no scalar [Formula: see text] bound state lighter than other hadrons. We discuss the TD mass in various methods, Gauged NJL model via ladder Schwinger-Dyson (SD) equation, straightforward calculations in the ladder SD/ Bethe-Salpeter equation, and the holographic approach including techni-gluon condensate. The TD may be discovered in LHC.

CLEAN PRECISION TESTS OF THE ELECTROWEAK THEORY

1992 ◽  
Vol 07 (12) ◽  
pp. 1009-1021 ◽  
Author(s):  
ZENRŌ HIOKI
Keyword(s):  
Experimental Data ◽  
Top Quark ◽  
Higgs Mass ◽  
Quantum Correction ◽  
Electroweak Theory ◽  
Weak Boson ◽  
Yukawa Couplings ◽  
Symmetry Breakdown ◽  
Electroweak Precision ◽  
Spontaneous Symmetry Breakdown

Present status of electroweak precision tests via the weak boson masses is reviewed, emphasizing that the standard SU(2) × U(1) theory is phenomenologically very successful also at quantum correction level. In particular, it is shown that the latest experimental data indicate the existence not only of the whole one-loop corrections but also of the non-decoupling top-quark effects, independent of the Higgs mass, which are a characteristic feature of theories with masses generated by spontaneous symmetry breakdown plus large Yukawa couplings.

UNIFIED ELECTROWEAK MODEL BASED ON SPACE–TIME AND ISOSPIN SYMMETRIES

2005 ◽  
Vol 20 (01) ◽  
pp. 175-198 ◽  
Author(s):  
D. SPEHLER ◽  
G. C. MARQUES
Keyword(s):  
Degrees Of Freedom ◽  
Space Time ◽  
Scalar Particles ◽  
Symmetry Breakdown ◽  
Vector Bosons ◽  
Rank 2 ◽  
Electroweak Model ◽  
Spontaneous Symmetry Breakdown ◽  
Internal Degrees Of Freedom

We propose a spinorial approach to the unified electroweak interactions, in which no use is made of spontaneous symmetry breakdown. No scalar particles are needed in order to break the symmetry. No reference is made to gauge symmetry. Our approach stresses the role of space–time and isospin symmetries in the build up of the electroweak model. Internal degrees of freedom, such as isospin, are incorporated in the theory by using spinors carrying isospin indices. All vector bosons are described by a rank 2 field in the spinorial and the isospinorial indices. Leptons are accomodated in a rank 1 spinor field and in a rank 2 isospin field as well. The dynamical variables of the theory are the chiral and isochiral components of these fields.

Spontaneous symmetry breakdown and Regge intercepts

1974 ◽  
Vol 50 (4) ◽  
pp. 475-478 ◽  
Author(s):  
R.F. Cahalan ◽  
P.H. Frampton
Keyword(s):  
Symmetry Breakdown ◽  
Spontaneous Symmetry Breakdown

Particle mixing from spontaneous symmetry breakdown

1970 ◽  
Vol 65 (1) ◽  
pp. 89-98 ◽  
Author(s):  
G. Cicogna ◽  
R. Vergara Caffarelli
Keyword(s):  
Symmetry Breakdown ◽  
Particle Mixing ◽  
Spontaneous Symmetry Breakdown

scholarly journals Restricted Weyl symmetry and spontaneous symmetry breakdown of conformal symmetry

2021 ◽  
Vol 36 (28) ◽  
pp. 2150203
Author(s):  
Ichiro Oda
Keyword(s):  
Conformal Symmetry ◽  
Goldstone Boson ◽  
Minkowski Spacetime ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Global Scale ◽  
Special Conformal Transformation ◽  
Symmetry Breakdown ◽  
Weyl Symmetry ◽  
Spontaneous Symmetry Breakdown

In this paper, we elucidate the relation between the restricted Weyl symmetry and spontaneous symmetry breakdown of conformal symmetry. Using a scalar–tensor gravity, we show that the restricted Weyl symmetry leads to spontaneous symmetry breakdown of a global scale symmetry when the vacuum expectation value of a scalar field takes a nonzero value. It is then shown that this spontaneous symmetry breakdown induces spontaneous symmetry breakdown of special conformal symmetry in a flat Minkowski spacetime, but the resultant Nambu–Goldstone boson is not an independent physical mode but expressed in terms of the derivative of the dilaton which is the Nambu–Goldstone boson of the global scale symmetry. In other words, the theories which are invariant under the general coordinate transformation and the restricted Weyl transformation exhibit a Nambu–Goldstone phase where both special conformal transformation and dilatation are spontaneously broken while preserving the Poincaré symmetry.

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