scholarly journals ON FERMION ZERO MODES IN INSTANTON V - A MODELS WITH SPONTANEOUS SYMMETRY BREAKING

1994 ◽  
Vol 09 (08) ◽  
pp. 715-723
Author(s):  
KAMRAN SARIRIAN
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Electroweak Theory ◽  
Yukawa Couplings ◽  
Zero Modes ◽  
Left Handed ◽  
Fermion Masses ◽  
Left And Right

The left- and right-handed fermion zero modes are examined. Their behavior under the variation of the size of the instanton, ρ I , and the size of the Higgs core, ρ H , for a range of Yukawa couplings corresponding to the fermion masses in the electroweak theory are studied. It is shown that the characteristic radii of the zero modes, in particular those of the left-handed fermions, are locked to the instanton size, and are not affected by the variation of ρ H , except for fermion masses much larger than those in the standard electroweak theory.

scholarly journals THEORY OF ELECTROWEAK INTERACTIONS WITHOUT SPONTANEOUS SYMMETRY BREAKING

2001 ◽  
Vol 16 (25) ◽  
pp. 4171-4188 ◽  
Author(s):  
BING AN LI
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Z Boson ◽  
W Boson ◽  
Axial Vector ◽  
Fermion Mass ◽  
Electroweak Theory ◽  
Intermediate Boson ◽  
Generating Functional ◽  
Fermion Masses

An electroweak theory without spontaneous symmetry breaking is studied in this paper. A new symmetry breaking of SU (2)L × U (1), axial-vector symmetry breaking, caused by the combination of the axial-vector component of the intermediate boson and the fermion mass is found in electroweak theory. The mass of the W boson is resulted in the combination of the axial-vector symmetry breaking and the explicit symmetry breaking by the fermion masses. The Z boson gains mass from the axial-vector symmetry breaking only. [Formula: see text], [Formula: see text], and [Formula: see text] are obtained. They are in excellent agreement with data. The SU (2)L × U (1) invariant generating functional of the Green functions is constructed and the theory is proved to be renormalizable.

scholarly journals ANOMALOUS FERMION MASS GENERATION AT THREE LOOPS

2013 ◽  
Vol 28 (22) ◽  
pp. 1350083 ◽  
Author(s):  
APOSTOLOS PILAFTSIS
Keyword(s):  
Gauge Theory ◽  
Quantum Gravity ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Model Building ◽  
Heavy Fermions ◽  
Fermion Mass ◽  
Mass Generation ◽  
Fermion Masses ◽  
Gravity Effects

We present a novel mechanism for generating fermion masses through global anomalies at the three-loop level. In a gauge theory, global anomalies are triggered by the possible existence of scalar or pseudoscalar states and heavy fermions, whose masses may not necessarily result from spontaneous symmetry breaking. The implications of this mass-generating mechanism for model building are discussed, including the possibility of creating low-scale fermion masses by quantum gravity effects.

scholarly journals STANDARD MODEL IN AdS SLICE WITH UV-LOCALIZED HIGGS FIELD

2010 ◽  
Vol 25 (18n19) ◽  
pp. 3641-3660
Author(s):  
SERGEY MIRONOV ◽  
MIKHAIL OSIPOV ◽  
SABIR RAMAZANOV
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Gauge Boson ◽  
Higgs Field ◽  
Mass Generation ◽  
Yukawa Couplings ◽  
Fermion Fields ◽  
Suppression Mechanism ◽  
Neutrino Mass Generation

We discuss five-dimensional Standard Model in a slice of AdS space–time with the Higgs field residing near or on the UV brane. Allowing fermion fields to propagate in the bulk, we obtain the hierarchy of their masses and quark mixings without introducing large or small Yukawa couplings. However, the interaction of fermions with the Higgs and gauge boson KK excitations gives rise to FCNC with no built-in suppression mechanism. This strongly constrains the scale of KK masses. We also discuss neutrino mass generation via KK excitations of the Higgs field. We find that this mechanism is subdominant in the scenarios of spontaneous symmetry breaking we consider.

Masses of W and Z bosons without spontaneous symmetry breaking

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 351-353
Author(s):  
Bing An Li
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Axial Vector ◽  
Z Bosons ◽  
Dynamical Symmetry ◽  
Fermion Mass ◽  
Electroweak Theory ◽  
Dynamical Symmetry Breaking ◽  
Vector Component ◽  
The Masses

A new dynamical symmetry breaking of SU(2)L × U(1) caused by the combination of the axial-vector component and the fermion mass is found in electroweak theory. The masses of the W and the Z bosons are obtained to be [Formula: see text] and [Formula: see text]. The Fermi constant is determined to be [Formula: see text].

scholarly journals NOTE ON TRIANGLE ANOMALIES AND ASSIGNMENT OF SINGLET IN 331-LIKE MODEL

2002 ◽  
Vol 17 (27) ◽  
pp. 1813-1823 ◽  
Author(s):  
T. KIYAN ◽  
T. MAEKAWA ◽  
S. YOKOI
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Complex Conjugate ◽  
Scalar Representation ◽  
Left Handed

It is pointed out that in the 331-like model which uses both fundamental and complex conjugate representations for an assignment of the representations to the left-handed quarks and the scalar representation to their corresponding right-handed counterparts, the nature of the scalar should be taken into account in order to make the fermion triangle anomalies in the theory anomaly-free, i.e. renormalizable in a sense with no anomalies, even after the spontaneous symmetry breaking.

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