Approximating chiral quark models with linear σ-models

Scalar-isoscalar states (J P C = 0 ++ ) are investigated within the large-Nc Regge approach. We elaborate on the consequences of including the lightest f0(600) scalar-isoscalar state into such an analysis, where the position of f0(600) fits very well into the pattern of the radial Regge trajectory. Furthermore, we point out that the pion and nucleon spin-0 gravitational form factors, recently measured on the lattice, provide valuable information on the low-mass spectrum of the scalarisoscalar states on the basis of the scalar-meson dominance in the spin-0 channel. Through the fits to these data we find mσ = 450 − 600 MeV. We compare the predictions of various fits and methods. An analysis of the QCD condensates in the two-point correlators provides further constraints on the parameters of the scalar-isoscalar sector. We find that a simple two-state model suggests a meson nature of f0 (600), and a glueball nature of f0 (980), which naturally explains the ratios of various coupling constants. Finally, we note that the fine-tuned condition of the vanishing dimension-2 condensate in the Regge approach with infinitely many scalar-isoscalar states yields a reasonable value for the mass of the lighest glueball state.

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“…one gets an extension of the linear sigma model with the so-called A-term [109], allowed in the linear realization of the chiral symmetry:…”

Section: Appendix A: the ζ-Regularizationmentioning

confidence: 99%

Scalar-isoscalar states in the large-NcRegge approach

2010

Self Cite

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“…At certain values of temperature and density, the equations (9)- (12) together with normalization condition (18) and boundary conditions (19), (20) which are nonlinear ordinary differential equations could be numerically solved. Using this solution, the physical properties of the three-quark system can be calculated.…”

Section: The Baryon Mass Calculation In Mediummentioning

confidence: 99%

“…The chiral soliton model could be solved in the mean-field approximation. A semiclassical soliton solution is referred to a baryon, and the baryon properties can be derived easily from the soliton solution [15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

The baryon mass calculation in the chiral soliton model at finite temperature and density

Zhang

Dong

Shu

2015

Int. J. Mod. Phys. E

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In the mean-field approximation, we have studied the soliton which is embedded in a thermal medium within the chiral soliton model. The energy of the soliton or the baryon mass in the thermal medium has been carefully evaluated, in which we emphasize that the thermal effective potential in the soliton energy should be properly treated in order to derive a finite and well-defined baryon mass out of the thermal background. The result of the baryon mass at finite temperatures and densities in chiral soliton model are clearly presented.

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“…During the last few years, there has been intense interest in various chiral quark models to the description of nucleon properties, such as the perturbative chiral quark model [9][10][11][12], extended Skyrme model [13,14] and extended linear sigma model [15][16][17]. The perturbative chiral quark model is an effective model of baryons based on chiral symmetry.…”

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confidence: 99%

Effect of the A-Term on the Nucleon Properties in the Extended Linear Sigma Model

Abu‐Shady

2008

Int J Theor Phys

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In this paper, the effect of the gradient-expanded meson term on the nucleon properties is investigated. The A-term is included in the extended linear sigma model in the framework of some aspects of QCD. The field equations have been solved in the mean-field approximation for the hedgehog baryon state. We find that the inclusion of the new term improves the description of the nucleon properties in comparison with other models.Keywords Mean-field approximation · Nucleon properties · Linear sigma model IntroductionIt is now becoming clear that the chiral symmetry of the QCD Lagrangian and its spontaneous breaking [1] play a very important role in determining the structure of low-mass hadrons, which consist of u, d and s quarks, and simultaneously play a crucial role in hadron correlators in mediating the spontaneous chiral symmetry breaking [2, 3].One of the effective models in describing hadron properties is the linear sigma model which has been suggested earlier by Gell-Mann and Levy [4] to describe nucleons interacting via sigma (σ ) and pion (π ) exchanges. This model is a principal example of spontaneous symmetry breaking. Some of the consequences of this model, however, are known to be in conflict with observation. Notably, the isoscalar pion-nucleon (πN ) scattering length predicted by the model is larger than experimental value by an order of magnitude; see e.g. Refs.[5-8]. Many solutions for this model have already been suggested. Birse and Banerjee [5] constructed equations of motion treating both the σ -and π -fields as time-independent classical fields and quarks in the hedgehog spinor state. Birse [6] generalized this mean-field model to include angular and momentum and isospin projection. Goeke et al. [7] investigated hadron properties in a chiral model for the nucleon based on the linear sigma model with scalar-isoscalar and scalar-isovector mesons coupled to quarks using the coherent pair M. Abu-Shady ( )

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Approximating chiral quark models with linear σ-models

Cited by 21 publications

References 48 publications

Scalar-isoscalar states in the large-NcRegge approach

Scalar-isoscalar states in the large-NcRegge approach

The baryon mass calculation in the chiral soliton model at finite temperature and density

Effect of the A-Term on the Nucleon Properties in the Extended Linear Sigma Model

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