Chiral-symmetry order parameter, the lattice, and nucleosynthesis

1987 ◽  
Vol 36 (10) ◽  
pp. 3291-3293 ◽  
Author(s):  
Larry McLerran
Keyword(s):  
Chiral Symmetry ◽  
Order Parameter

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 Chiral symmetry breaking, entanglement, and the nucleon spin decomposition

2019 ◽  
Vol 35 (08) ◽  
pp. 2050048 ◽  
Author(s):  
Silas R. Beane ◽  
Peter J. Ehlers
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Order Parameter ◽  
Chiral Symmetry Breaking ◽  
Entanglement Entropy ◽  
Reduced Density Matrix ◽  
Nucleon Spin ◽  
Maximal Entanglement ◽  
Nucleon State ◽  
Reduced Density

The nucleon is naturally viewed as a bipartite system of valence spin — defined by its non-vanishing chiral charge — and non-valence or sea spin. The sea spin can be traced over to give a reduced density matrix, and it is shown that the resulting entanglement entropy acts as an order parameter of chiral symmetry breaking in the nucleon. In the large-[Formula: see text] limit, the entanglement entropy vanishes and the valence spin accounts for all of the nucleon spin, while in the limit of maximal entanglement entropy, the nucleon loses memory of the valence spin and consequently has spin dominated by the sea. The nucleon state vector in the chiral basis, fit to low-energy data, gives a valence spin content consistent with experiment and lattice QCD determinations, and has large entanglement entropy.

scholarly journals CHIRAL SYMMETRY IN NUCLEI THEORETICAL EXPECTATIONS AND HARD FACTS

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2371-2380 ◽  
Author(s):  
ULRICH MOSEL
Keyword(s):  
Phase Transition ◽  
Primary Production ◽  
Chiral Symmetry ◽  
Order Parameter ◽  
Chiral Condensate ◽  
Final State ◽  
Chiral Phase ◽  
Decay Products ◽  
Final State Interactions ◽  
Robust Result

It is widely believed that chiral symmetry is restored not only at high temperatures, but also at high nuclear densities. The drop of the order parameter of the chiral phase transition, the chiral condensate, with density has indeed been calculated in various models and is as such a rather robust result. In this talk I point out that the connection of this property with actual observables is far less clear. For this task a good hadronic description of the primary production of hadrons, their propagation inside the nuclear medium, their decay and the propagation of the decay products through the medium to the detector all have to be treated with equal accuracy and weight. In this talk I illustrate with the examples of ω production and π0π0 production how important in particular final state interactions are.

MASSLESSNESS OF PHOTON AND CHERN-SIMONS TERM IN (2 + 1)-DIMENSIONAL QED

1990 ◽  
Vol 05 (31) ◽  
pp. 2661-2668 ◽  
Author(s):  
A. KOVNER ◽  
B. ROSENSTEIN
Keyword(s):  
Symmetry Breaking ◽  
Global Symmetries ◽  
Chiral Symmetry ◽  
Order Parameter ◽  
Goldstone Theorem ◽  
Chern Simons ◽  
Direct Correspondence ◽  
Topological Mass

We study the realization of global symmetries in (2 + 1)-dimensional QED with two fermion flavors. It is shown that, in a certain range of mass parameters, the chiral symmetry [Formula: see text] and the flux symmetry Φ = ∫d2xB are both spontaneously broken, but the combination I = Q5 − sign (m)e/πΦ remains unbroken. The photon is identified with the corresponding massless excitation, which is required in this case by Goldstone theorem. An order parameter vanishes and chiral and flux symmetries are realized in the Kosterlitz-Thouless mode. Outside this range of parameters the vacuum is symmetric and simultaneously the photon's topological mass is generated. Similar symmetry breaking pattern U (1) ⊗ U (1) → U (1) is realized in Chern-Simons electrodynamics for a particular value of the bare CS-term coefficient at which the "statistical photon" becomes massless. We point out the direct correspondence of this model to the superconducting anyon gas.

scholarly journals STRONG COUPLING QED BREAKS CHIRAL SYMMETRY

1992 ◽  
Vol 07 (30) ◽  
pp. 2811-2818 ◽  
Author(s):  
GORDON W. SEMENOFF
Keyword(s):  
Strong Coupling ◽  
Chiral Symmetry ◽  
Quantum Electrodynamics ◽  
Order Parameter ◽  
Chiral Symmetry Breaking ◽  
Mass Operator ◽  
Strong Coupling Limit ◽  
Heisenberg Antiferromagnet ◽  
Expectation Value ◽  
Néel Order

We show that the strong coupling limit of d-dimensional quantum electrodynamics with 2d/2[d/2] flavors of fermions can be mapped onto the s=1/2 quantum Heisenberg antiferromagnet in d–1 space dimensions. We use this mapping to prove that the strong coupling limit of QED breaks chiral symmetry. The staggered Néel order parameter of the antiferromagnet is the expectation value of a mass operator in QED and the spin-waves are pions. We speculate that the chiral symmetry breaking phase transition corresponds to a transition between the flux phase and the conventional Néel ordered phase of an antiferromagnetic t-J model.

EFFECT OF ORDER PARAMETER RELAXATION ON JOSEPHSON JUNCTION TRANSIENTS

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-550-C6-551
Author(s):  
H. Suhl ◽  
J. Hurell ◽  
A. H. Silver ◽  
Y. Song
Keyword(s):  
Josephson Junction ◽  
Order Parameter
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