The Extended Chiral Quark Model and QCD

Abstract

We consider the low energy effective action of QCD below the chiral symmetry breaking scale, including, in Wilson's spirit, all operators of dimensionality less or equal to 6 which can be built with quark and chiral fields. The effect of the residual gluon interactions is contained in a number of coupling constants, whose running is studied. The resulting model is an extension of both the chiral quark model and the Nambu-Jona-Lasinio one. Constraints on the coefficients of the effective lagrangian are derived from the requirement of chiral symmetry restoration at energies above the chiral symmetry breaking scale, from matching to QCD at intermediate scales, and by fitting some hadronic observables. In this model two types of pseudoscalar states (massless pions and massive Π-mesons), as well as one scalar one arise as a consequence of dynamical chiral symmetry breaking. Their masses and coupling constants are studied. We also predict a number of low energy structural constants. We find out that QCD favours a low-energy effective theory which is largely dominated by the simplest chiral quark model, whereas higher dimensional operators (such as those of the Nambu-Jona-Lasinio type) can be assumed to be small.

43 pages, Sec.7 is slightly corrected, fit and conclusions are unchanged

References in corpus (2)

• Direct extraction of the chiral quark condensate and bounds on the light quark masses
• Beyond the Narrow Resonance Approximation: Decay Constant and Width of the First Pion-Excitation State

Cited by in corpus (30)

• N/D Description of Two Meson Amplitudes and Chiral Symmetry
• Longitudinal short-distance constraints for the hadronic light-by-light contribution to $(g-2{)}_{\mu }$ with large-$N_c$ Regge models
• Matching Regge Theory to the OPE
• Parity doubling in particle physics
• The 7/11 rule: an estimate of m_rho/f_pi
• The decay constant of the first excited pion from lattice QCD
• On the possibility of P-violation at finite baryon-number densities
• Holographic like models as a five-dimensional rewriting of large-Nc QCD
• Qualitative solution of QCD sum rules
• Distribution amplitudes of radially-excited pi- and K-mesons
• Pion condensation of quark matter in the static Einstein universe
• Cluster duality
• Decay constants of the pion and its excitations in holographic QCD
• The Effective Electroweak Chiral Lagrangian: The Matter Sector
• Quark and pion effective couplings from polarization effects
• Photoproduction of scalar mesons on protons and nuclei
• SU(2) higher-order effective quark interactions from polarization
• SU(2) low energy quark effective couplings in weak external magnetic field
• Electromagnetic penguin operators and direct CP violation in K --> pi l^+ l^-
• Parity doubling from Weinberg sum rules
• Weinberg like sum rules revisited
• The quark loop calculation of the gamma -> 3 pi form factor
• Radial excitations of mesons and nucleons from QCD sum rules
• Radially excited pion: electromagnetic form factor and the box contribution to the muon's $g-2$
• The Extended Chiral Quark Model confronts QCD
• Quasilocal Quark Models as Effective Theory of Non-perturbative QCD
• Axial anomaly and the interplay of quark loops with pseudoscalar and vector mesons in the gamma* --> pi+ pi0 pi- process
• High Energy Theorems at Large-N
• Vector meson decays from the Extended Chiral Quark Model
• Axial coupling from matching constituent quark model to QCD