GAUGE INVARIANT STUDY OF THE STRONG COUPLING PHASE OF MASSLESS QUANTUM ELECTRODYNAMICS

1990 ◽  
Vol 05 (09) ◽  
pp. 1789-1800 ◽  
Author(s):  
M. UKITA ◽  
M. KOMACHIYA ◽  
R. FUKUDA
Keyword(s):  
Strong Coupling ◽  
Quantum Electrodynamics ◽  
Chiral Symmetry Breaking ◽  
Renormalization Scheme ◽  
Gauge Parameter ◽  
Coupling Constant ◽  
Critical Coupling ◽  
Gauge Invariant ◽  
Coupling Phase ◽  
Massless Quantum

The strong coupling phase of massless Quantum Electrodynamics is studied in a gauge invariant way. The formalism is given in which the order parameter of the chiral symmetry breaking is calculated through the vacuum polarization diagrams. Applying this method, the critical coupling constant is shown to exist that is independent of the gauge parameter but is now dependent on the ratio of the two kinds of cutoff. Implication of this new parameter on the renormalization scheme in the strong coupling phase is discussed.

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.

scholarly journals RENORMALIZATION GROUP AND TRIVIALITY IN NONCOMPACT LATTICE QED WITH LIGHT FERMIONS

1992 ◽  
Vol 07 (38) ◽  
pp. 3561-3568 ◽  
Author(s):  
V. AZCOITI ◽  
G. Di CARLO ◽  
A.F. GRILLO
Keyword(s):  
Renormalization Group ◽  
Strong Coupling ◽  
Weak Coupling ◽  
Functional Dependence ◽  
Average Energy ◽  
Numerical Results ◽  
Coupling Constant ◽  
Coupling Phase ◽  
Show Evidence

In the framework of noncompact lattice QED with light fermions, we derive the functional dependence of the average energy per plaquette on the bare parameters using blockspin Renormalization Group arguments and assuming that the renormalized coupling vanishes. Our numerical results for this quantity in 84 and 104 lattices show evidence for triviality in the weak coupling phase and point to a nonvanishing value for the renormalized coupling constant in the strong coupling phase.

A SEMIPHENOMENOLOGICAL DETERMINATION OF QUARK CONDENSATE

1994 ◽  
Vol 09 (04) ◽  
pp. 499-506 ◽  
Author(s):  
XIN-HENG GUO ◽  
TAO HUANG
Keyword(s):  
Renormalization Group ◽  
Chiral Limit ◽  
Chiral Symmetry Breaking ◽  
Quark Condensate ◽  
Coupling Constant ◽  
Critical Coupling ◽  
Group Invariant ◽  
The One ◽  
Consistent Equation

A consistent equation for the quark condensate in the chiral limit provides a determination of the renormalization-group-invariant quark condensate. A critical point at which the strong coupling constant is big enough for chiral symmetry breaking to take place is found. They are analyzed at the one- and two-loop levels respectively. An intuitive picture of the condensation above the critical coupling constant is discussed.

OBSERVABLE CONSEQUENCES OF THE STRONG COUPLING PHASE OF QED HYPOTHESIZED NEAR THE SURFACE OF LARGE-Z NUCLEI

1990 ◽  
Vol 05 (05) ◽  
pp. 309-314 ◽  
Author(s):  
M. INOUE ◽  
T. MUTA ◽  
J. SAITO ◽  
H.-L. YU
Keyword(s):  
Strong Coupling ◽  
Quantum Electrodynamics ◽  
External Disturbance ◽  
Surface Region ◽  
Heavy Ion ◽  
Coincidence Measurement ◽  
Heavy Nuclei ◽  
Coupling Phase ◽  
Electron Positron ◽  
Large Atomic Number

We discuss observable effects of the assumption that the strong coupling phase of quantum electrodynamics is realized in the surface region of heavy nuclei with large atomic number Z under a suitable external disturbance. We present some comments on anomalous peaks in electron-positron systems observed in heavy ion reactions and on effects expected in electron and positron scatterings off large-Z nuclei. We propose some experiments to test our assumption: (1) coincidence measurement of e+e− and γγ signals from the decays of large-Z nuclei, and (2) spectroscopy of large-Z muonic atoms.

PHOTON PAIRING AND THE STRONG COUPLING PHASE OF MASSIVE QUANTUM ELECTRODYNAMICS COOPER EQUATION

1990 ◽  
Vol 05 (06) ◽  
pp. 381-390 ◽  
Author(s):  
T. INAGAKI ◽  
M. KOMACHIYA ◽  
R. FUKUDA
Keyword(s):  
Fine Structure ◽  
External Field ◽  
Strong Coupling ◽  
Quantum Electrodynamics ◽  
Structure Constant ◽  
Critical Value ◽  
Low Energy ◽  
Fine Structure Constant ◽  
Coupling Phase ◽  
Effective Lagrangian

Through the Cooper equation of the photon pairing, the instability of the normal vacuum of the Quantum Electrodynamics with the massive electron is studied. Using the low energy effective Lagrangian, the normal vacuum is shown to be unstable against the condensation of the photon pairs above the critical value of the fine structure constant. These agree with the previous results obtained by the Bethe-Salpeter equation. The presence of the weak electric external field enhances the instability thus lowering the critical value. This can be a basis for the explanation of the anomalous GSI e+e− events.

CRITICAL LINE AND BETHE-SALPETER EQUATION IN STRONG-COUPLING QED WITH FOUR-FERMION INTERACTIONS

1989 ◽  
Vol 04 (07) ◽  
pp. 605-612 ◽  
Author(s):  
M. INOUE ◽  
T. MUTA ◽  
T. OCHIUMI
Keyword(s):  
Symmetry Breaking ◽  
Strong Coupling ◽  
Chiral Symmetry ◽  
Quantum Electrodynamics ◽  
Phase Structure ◽  
Bound States ◽  
Critical Line ◽  
Chiral Symmetry Breaking ◽  
Electron Positron ◽  
Symmetric Phase

On the basis of Bethe-Salpeter equations for electron-positron bound states in strong-coupling quantum electrodynamics with additional four-fermion interactions, the formula for the critical line dividing the chiral-symmetry-breaking phase from the symmetric phase is derived. The beta functions near the critical line are calculated explicitly and the phase structure is discussed based on these beta functions.

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