Low-energy photo- and electroproduction for physical pions. I. Ward-identity and chiral-symmetry-breaking structure

1979 ◽  
Vol 20 (5) ◽  
pp. 1069-1080 ◽  
Author(s):  
J. T. MacMullen ◽  
M. D. Scadron
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Ward Identity ◽  
Chiral Symmetry Breaking ◽  
Low Energy

scholarly journals Chiral symmetry breaking by monopole condensation

2017 ◽  
Vol 32 (23n24) ◽  
pp. 1750139 ◽  
Author(s):  
Aiichi Iwazaki
Keyword(s):  
Symmetry Breaking ◽  
Pair Production ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Chiral Condensate ◽  
Low Energy ◽  
Chiral Anomaly ◽  
Symmetric Pair ◽  
Color Charge ◽  
Massless Quark

Under the assumption of Abelian dominance in QCD, we have shown that chiral condensate is locally present around each QCD monopole. The essence is that either charge or chirality of a quark is not conserved, when the low energy massless quark collides with QCD monopole. In reality, the charge is conserved so that the chirality is not conserved. Reviewing the presence of the local chiral condensate, we show by using chiral anomaly that chiral nonsymmetric quark pair production takes place when a color charge is putted in a vacuum with monopole condensation, while chiral symmetric pair production takes place in a vacuum with no monopole condensation. Our results strongly indicate that the chiral symmetry is broken by the monopole condensation.

scholarly journals RELATING THE PION DECAY CONSTANT TO THE CHIRAL RESTORATION TEMPERATURE

1995 ◽  
Vol 10 (08) ◽  
pp. 1169-1179 ◽  
Author(s):  
N. BILIĆ ◽  
J. CLEYMANS ◽  
M. D. SCADRON
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Decay Constant ◽  
Chiral Symmetry Breaking ◽  
Low Energy ◽  
Pion Decay ◽  
Chiral Symmetry Restoration ◽  
Pion Decay Constant ◽  
Sigma Meson ◽  
The Relationship

We review the relationship between the pion decay constant fπ, the chiral symmetry restoration temperature Tc and the phenomenology of low energy chiral symmetry breaking in view of the recent confirmation of the existence of a sigma meson with a mass of 600–700 MeV.

scholarly journals Minimally doubled fermions and spontaneous chiral symmetry breaking

2018 ◽  
Vol 175 ◽  
pp. 04002 ◽  
Author(s):  
Rudina Osmanaj (Zeqirllari) ◽  
Dafina Hyka (Xhako)
Keyword(s):  
Symmetry Breaking ◽  
Dirac Operator ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Chiral Condensate ◽  
Low Energy ◽  
Reliable Determination ◽  
Spontaneous Chiral Symmetry Breaking ◽  
Energy Physics

Chiral symmetry breaking in massless QCD is a very important feature in the current understanding of low energy physics. Low - lying Dirac modes are suitable to help us understand the spontaneous chiral symmetry breaking, since the formation of a non zero chiral condensate is an effect of their accumulation near zero. The Banks – Casher relation links the spectral density of the Dirac operator to the condensate with an identity that can be read in both directions. In this work we propose a spectral method to achieve a reliable determination of the density of eigenvalues of Dirac operator near zero using the Gauss – Lanczos quadrature. In order to understand better the dynamical chiral symmetry breaking and use the method we propose, we have chosen to work with minimally doubled fermions. These kind of fermions have been proposed as a strictly local discretization of the QCD fermions action, which preserves chiral symmetry at finite cut-off. Being chiral fermions, is easier to work with them and their low - lying Dirac modes and to understand the dynamical spontaneous chiral symmetry breaking.

CHIRAL SYMMETRY BREAKING AND THE GLUON CONDENSATE

1993 ◽  
Vol 08 (04) ◽  
pp. 335-339
Author(s):  
M. FABER ◽  
A.N. IVANOV ◽  
M. NAGY ◽  
N.I. TROITSKAYA
Keyword(s):  
Magnetic Field ◽  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Sum Rules ◽  
Chiral Symmetry Breaking ◽  
Gluon Condensate ◽  
Quark Condensate ◽  
Low Energy ◽  
Qcd Sum Rules ◽  
Energy Approximation

For the low-energy approximation of QCD, the extended Nambu-Jona-Lasinio model has been used. Quarks interact with an external homogeneous color-magnetic field, simulating the contribution of the gluon condensate. The value of the gluon condensate, needed to reach the correct value of the quark condensate, is determined and agrees well with the value obtained from QCD sum rules.

scholarly journals COMMENTS ON THE VACUUM ORIENTATIONS IN QCD

1992 ◽  
Vol 07 (33) ◽  
pp. 3147-3154 ◽  
Author(s):  
ZHENG HUANG ◽  
K.S. VISWANATHAN ◽  
DAN-DI WU
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Ward Identity ◽  
Chiral Symmetry Breaking ◽  
Dynamical Chiral Symmetry Breaking ◽  
Qcd Vacuum ◽  
Quark Field ◽  
Definition Of ◽  
Anomalous Ward Identity ◽  
Vacuum Alignment

We study the QCD vacuum orientation angles in correlation with the strong CP phases. A vacuum alignment equation of the dynamical chiral symmetry breaking is derived based on the anomalous Ward identity. It is emphasized that a chiral rotation of the quark field causes a change of the vacuum orientation and a change in the definition of the light pseudoscalar generators. As an illustration of the idea, η→2π decays are carefully studied in different chiral frames.

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