VACUUM POLARIZATION AND DYNAMICAL CHIRAL SYMMETRY BREAKING IN QUANTUM ELECTRODYNAMICS

1990 ◽  
Vol 05 (02) ◽  
pp. 133-142 ◽  
Author(s):  
V.P. GUSYNIN
Keyword(s):  
Chiral Symmetry ◽  
Quantum Electrodynamics ◽  
Vacuum Polarization ◽  
Chiral Symmetry Breaking ◽  
Local Limit ◽  
Mass Function ◽  
Dyson Equation ◽  
Fermion Mass ◽  
Large Coupling ◽  
Large Coupling Constant

The Schwinger-Dyson equation for the fermion mass function taking into account the vacuum polarization effects is considered. It is shown that even in the “zero-charge” situation there exists, at rather large coupling constant (α > αc), a solution with spontaneously broken chiral symmetry. The existence of the local limit in the model concerned is discussed.

scholarly journals Confinement, Chiral Symmetry Breaking and it's Restoration using Dual QCD Formalism

2018 ◽  
Vol 177 ◽  
pp. 09009 ◽  
Author(s):  
Garima Punetha ◽  
H.C. Chandola
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Close Relation ◽  
Mass Function ◽  
Dyson Equation ◽  
Quark Condensate ◽  
Abelian Gauge ◽  
Dynamical Parameters ◽  
Symmetry Structure

Utilizing the dual QCD model in term of magnetic symmetry structure of non- Abelian gauge theories, the dynamical chiral-symmetry breaking using Schwinger-Dyson equation has been investigated. A close relation among the color confinement and chiralsymmetry breaking has been observed and demonstrated by computing dynamical parameters. The recovery of the chiral symmetry has also been discussed at finite temperature through the variation of quark mass function and quark condensate which gradually decreases with temperature and vanishes suddenly near the critical temperature.

scholarly journals Electroweak SU(2)L × U(1)Y model with strong spontaneously fermion-mass-generating gauge dynamics

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Petr Beneš ◽  
Jiří Hošek ◽  
Adam Smetana
Keyword(s):  
Chiral Symmetry Breaking ◽  
Axial Vector ◽  
Higgs Sector ◽  
Dyson Equation ◽  
Mass Splitting ◽  
Fermion Mass ◽  
Goldstone Bosons ◽  
The Standard Model ◽  
Exploratory Stage ◽  
The Masses

Abstract Higgs sector of the Standard model (SM) is replaced by quantum flavor dynamics (QFD), the gauged flavor SU(3)f symmetry with scale Λ. Anomaly freedom requires addition of three νR. The approximate QFD Schwinger-Dyson equation for the Euclidean infrared fermion self-energies Σf(p2) has the spontaneous-chiral-symmetry-breaking solutions ideal for seesaw: (1) Σf(p2) = $$ {M}_{fR}^2/p $$ M fR 2 / p where three Majorana masses MfR of νfR are of order Λ. (2) Σf(p2) = $$ {m}_f^2/p $$ m f 2 / p where three Dirac masses mf = m(0)1 + m(3)λ3 + m(8)λ8 of SM fermions are exponentially suppressed w.r.t. Λ, and degenerate for all SM fermions in f. (1) MfR break SU(3)f symmetry completely; m(3), m(8) superimpose the tiny breaking to U(1) × U(1). All flavor gluons thus acquire self-consistently the masses ∼ Λ. (2) All mf break the electroweak SU(2)L × U(1)Y to U(1)em. Symmetry partners of the composite Nambu-Goldstone bosons are the genuine Higgs particles: (1) three νR-composed Higgses χi with masses ∼ Λ. (2) Two new SM-fermion-composed Higgses h3, h8 with masses ∼ m(3), m(8), respectively. (3) The SM-like SM-fermion-composed Higgs h with mass ∼ m(0), the effective Fermi scale. Σf(p2)-dependent vertices in the electroweak Ward-Takahashi identities imply: the axial-vector ones give rise to the W and Z masses at Fermi scale. The polar-vector ones give rise to the fermion mass splitting in f. At the present exploratory stage the splitting comes out unrealistic.

Determine the critical fermion flavor in three-dimensional QED using nonlocal gauge

2014 ◽  
Vol 29 (33) ◽  
pp. 1450159
Author(s):  
Hua Jiang ◽  
Yong-Long Wang ◽  
Wei-Tao Lu ◽  
Chuan-Cong Wang
Keyword(s):  
Symmetry Breaking ◽  
Critical Point ◽  
Chiral Symmetry ◽  
Gauge Boson ◽  
Quantum Electrodynamics ◽  
Chiral Symmetry Breaking ◽  
Three Dimensional ◽  
Gauge Parameter ◽  
Dynamical Chiral Symmetry Breaking

We determine the critical fermion flavor for dynamical chiral symmetry breaking in three-dimensional quantum electrodynamics using nonlocal gauge (gauge parameter depends on the momentum or coordinate). The coupled Dyson–Schwinger equations of the fermion and gauge boson propagators are considered in the vicinity of the critical point. Illustrated by using the transverse vertex proposed by Bashir et al., we show that: for a variety of the transverse vertex, the critical flavor is still 128/3π2, the same as using the bare vertex.

PHASE STRUCTURE OF QED3 AT FINITE CHEMICAL POTENTIAL AND TEMPERATURE

2007 ◽  
Vol 22 (06) ◽  
pp. 449-456 ◽  
Author(s):  
MIN HE ◽  
HONG-TAO FENG ◽  
WEI-MIN SUN ◽  
HONG-SHI ZONG
Keyword(s):  
Phase Diagram ◽  
Wave Function ◽  
Symmetry Breaking ◽  
Quantum Electrodynamics ◽  
Phase Structure ◽  
Chemical Potential ◽  
Chiral Symmetry Breaking ◽  
Three Dimensional ◽  
Mass Function ◽  
Wave Function Renormalization

We study the dynamical chiral symmetry breaking (DCSB) of three-dimensional quantum electrodynamics (QED3) at finite chemical potential and temperature in the framework of Dyson–Schwinger approach. Based on the rainbow approximation and assumption that the wave-function renormalization factor equals to one, the dynamically generated mass function is derived and then the corresponding phase diagram in the (T, μ) plane is obtained.

scholarly journals THERMAL RESTORATION OF CHIRAL SYMMETRY IN SUPERSYMMETRIC NAMBU–JONA-LASINIO MODEL WITH SOFT SUSY BREAKING

1998 ◽  
Vol 13 (15) ◽  
pp. 1235-1240 ◽  
Author(s):  
J. HASHIDA ◽  
T. MUTA ◽  
K. OHKURA
Keyword(s):  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Susy Breaking ◽  
Fermion Mass ◽  
Coupling Constant ◽  
Field Coupling ◽  
Unified Field ◽  
Supersymmetric Version ◽  
First Order Phase ◽  
Breaking Term

The supersymmetric version of the Nambu–Jona-Lasinio model is investigated in connection with the chiral symmetry breaking induced by a soft SUSY breaking term. It is found that the broken chiral symmetry due to the soft breaking term is restored at suitably high temperature and the symmetry restoration occurs as first-order phase transitions. The critical temperature at which the chiral symmetry is restored is determined as a function of the strength of the soft breaking term and the field coupling constant. The dynamical fermion mass is calculated at finite temperature. Some possible applications to the breaking scenario of unified field theories are discussed.

SPONTANEOUS CHIRAL-SYMMETRY BREAKING AND SCALING LAW IN THREE-DIMENSIONAL QED

1990 ◽  
Vol 05 (06) ◽  
pp. 407-416 ◽  
Author(s):  
KEI-ICHI KONDO ◽  
HAJIME NAKATANI
Keyword(s):  
Chiral Symmetry ◽  
Order Parameter ◽  
Chiral Symmetry Breaking ◽  
Scaling Law ◽  
Three Dimensional ◽  
Dyson Equation ◽  
Dirac Fermion ◽  
Dynamical Mass ◽  
Planar Approximation ◽  
Spontaneous Breakdown

We analyze the critical behavior associated with spontaneous breakdown of chiral symmetry in QED3 (three-dimensional QED with four-component Dirac fermion using the SD (Schwinger-Dyson) equation. In the quenched planar approximation, we find an approximate solution such that QED3 resides in only one phase where the chiral symmetry is broken. Moreover, we predict the scaling law for the dynamical mass and chiral order parameter by an analytic study of the SD equation, which is then confirmed by solving the SD equation numerically. This scaling law is consistent with the Monte Carlo result in the quenched approximation.

scholarly journals NEW ANGLE ON THE STRONG CP AND CHIRAL SYMMETRY PROBLEMS FROM A ROTATING MASS MATRIX

2009 ◽  
Vol 24 (01) ◽  
pp. 101-112 ◽  
Author(s):  
JOSÉ BORDES ◽  
HONG-MO CHAN ◽  
TSOU SHEUNG TSUN
Keyword(s):  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Mass Matrix ◽  
Energy Scale ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Quark Masses ◽  
Chiral Transformation ◽  
The Masses ◽  
Fermion Mass Matrix

It is shown that when the mass matrix changes in orientation (i.e. rotates) in generation space for a changing energy scale, the masses of the lower generations are not given just by its eigenvalues. In particular, these masses need not be zero even when the eigenvalues are zero. In that case, the strong CP problem can be avoided by removing the unwanted θ term by a chiral transformation not in contradiction with the nonvanishing quark masses experimentally observed. Similarly, a rotating mass matrix may shed new light on the problem of chiral symmetry breaking. That the fermion mass matrix may so rotate with the scale has been suggested before as a possible explanation for up–down fermion mixing and fermion mass hierarchy, giving results in good agreement with experiment.

DIMENSIONAL DEPENDENCE OF CHIRAL-SYMMETRY- BREAKING PHASE TRANSITION IN QUENCHED PLANAR QED

1989 ◽  
Vol 04 (22) ◽  
pp. 2155-2166 ◽  
Author(s):  
KEI-ICHI KONDO ◽  
HAJIME NAKATANI
Keyword(s):  
Phase Transition ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Scaling Law ◽  
Mean Field ◽  
Dyson Equation ◽  
Essential Singularity ◽  
Spontaneous Breaking ◽  
Planar Approximation ◽  
Singularity Type

We consider the critical behavior of the phase transition associated with the spontaneous breaking of chiral-symmetry in (QED) D, in the framework of the Schwinger-Dyson equation. Special attention is paid on the scaling law. While it is well known that quenched planar QED 4 obeys the Miransky scaling of the essential singularity type, our numerical calculations show that QED 5 and QED 6 do obey the mean-field type scaling, even in the quenched planar approximation. Thus the essential singularity type scaling in the cutoff QED is considered to be possible only when D=4 under the quenched planar approximation.

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