Current and constituent quark masses: Beyond chiral-symmetry breaking

1990 ◽  
Vol 41 (5) ◽  
pp. 1661-1666 ◽  
Author(s):  
D. Atkinson ◽  
P. W. Johnson
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Constituent Quark ◽  
Chiral Symmetry Breaking ◽  
Quark Masses

NEUTRAL PION PHOTOPRODUCTION ON THE PROTON AND THE CLOUDY-BAG MODEL

1992 ◽  
Vol 07 (21) ◽  
pp. 5231-5244
Author(s):  
A.N. TABACHENKO
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Electric Dipole ◽  
Neutral Pion ◽  
Chiral Symmetry Breaking ◽  
Pion Photoproduction ◽  
Additional Contribution ◽  
Bag Model ◽  
Neutral Pions ◽  
Quark Masses

In the cloudy-bag model, the value of the electric dipole amplitude of the photoproduction of neutral pions off protons at threshold connected with the additional contribution from the chiral symmetry breaking interaction is evaluated. If this additional contribution is included in the amplitude of the photoproduction of neutral pions off protons at threshold, the discrepancy between the LET predictions and the measured value of the electric dipole amplitude [Formula: see text] can be resolved for the values of quark masses and bag radii which are close to the generally used values.

Vacuum Structure, Chiral Symmetry Breaking and Radiative Decays of Vector Mesons

1997 ◽  
Vol 06 (01) ◽  
pp. 121-134
Author(s):  
A. R. Panda ◽  
K. C. Roy
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Radiative Decay ◽  
Constituent Quark ◽  
Chiral Symmetry Breaking ◽  
Vector Mesons ◽  
Model Calculations ◽  
Vacuum Structure ◽  
Quark Field ◽  
Decay Widths

The radiative decay widths of vector mesons were considered in a model involving chiral symmetry breaking through a nontrivial vacuum structure where the pion and kaon being treating consistently yield the constituent quark wave functions, approximately the same as that obtained from the gap equations and thus in a way determine the constituent quark field operators. Like its earlier success to some low energy hadronic phenomena, here also the model calculations of radiative decay widths of mesons are in reasonable agreements with other theoretical estimations as well as experimental measurements.

Dynamical chiral-symmetry breaking and determination of the quark masses

1988 ◽  
Vol 38 (1) ◽  
pp. 238-278 ◽  
Author(s):  
A. Barducci ◽  
R. Casalbuoni ◽  
S. De Curtis ◽  
D. Dominici ◽  
R. Gatto
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Dynamical Chiral Symmetry Breaking ◽  
Quark Masses

scholarly journals SOFTLY BROKEN N=2 QCD WITH MASSIVE QUARK HYPERMULTIPLETS, II

1998 ◽  
Vol 13 (11) ◽  
pp. 1847-1880 ◽  
Author(s):  
LUIS ÁLVAREZ-GAUMÉ ◽  
MARCOS MARIÑO ◽  
FREDERIC ZAMORA
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Pion Mass ◽  
Elliptic Functions ◽  
Numerical Control ◽  
Massive Quark ◽  
First Order ◽  
Quark Masses ◽  
First Order Phase

We analyze the vacuum structure of N=2, SU(2) QCD with massive quark hypermultiplets, once supersymmetry is softly broken down to N=0 with dilaton and mass spurions. We give general expressions for the low energy couplings of the effective potential in terms of elliptic functions to have a complete numerical control of the model. We study in detail the possible phases of the theories with Nf=1,2 flavors for different values of the bare quark masses and the supersymmetry breaking parameters and we find a rich structure of first order phase transitions. The chiral symmetry breaking pattern of the Nf=2 theory is considered, and we obtain the pion Lagrangian for this model up to two derivatives. Exact expressions are given for the pion mass and Fπ in terms of the magnetic monopole description of chiral symmetry breaking.

scholarly journals STRANGENESS AND CHIRAL SYMMETRY BREAKING

2011 ◽  
Vol 26 (04) ◽  
pp. 279-288 ◽  
Author(s):  
HARLEEN DAHIYA ◽  
NEETIKA SHARMA
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Significant Contribution ◽  
Constituent Quark ◽  
Chiral Symmetry Breaking ◽  
Quantitative Description ◽  
Constituent Quark Model ◽  
Matrix Elements ◽  
Qualitative And Quantitative

The implications of chiral symmetry breaking and SU(3) symmetry breaking have been studied in the chiral constituent quark model (χCQM). The role of hidden strangeness component has been investigated for the scalar matrix elements of the nucleon with an emphasis on the meson–nucleon sigma terms. The χCQM is able to give a qualitative and quantitative description of the "quark sea" generation through chiral symmetry breaking. The significant contribution of the strangeness is consistent with the recent available experimental observations.

VACUUM STRUCTURE, CHIRAL SYMMETRY BREAKING AND RADIATIVE DECAYS OF BARYONS

1996 ◽  
Vol 05 (03) ◽  
pp. 543-556
Author(s):  
A.R. PANDA ◽  
K.C. ROY
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Radiative Decay ◽  
Constituent Quark ◽  
Theoretical Calculations ◽  
Chiral Symmetry Breaking ◽  
Wave Functions ◽  
Radiative Decays ◽  
Vacuum Structure ◽  
Decays Of Baryons

Radiative decays of baryons are considered in a model involving chiral symmetry breaking through a nontrivial vacuum structure. Pion and kaon, being treated consistently within the model, yield to the constituent quark wave functions approximately in the same way as the wave functions from the gap equations, and thus in a way determine the constituent quark field operators. The model had a reasonable success earlier in its applications to some low energy hadronic phenomena, and here also estimates radiative decay widths of baryons in reasonable agreement with other theoretical calculations as well as the available experimental measurements.

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