T. Watabe

Baryons as non-topological chiral solitons

Abstract The present review gives a survey of recent developments and applications of the Nambu-Jona-Lasinio model with Nf = 2 and Nf = 3 quark flavors for the structure of baryons. The model is an effective chiral quark theory which incorporates the SU(Nf)L⊗SU(Nf)R⊗U(1)V approximate symmetry of Quantum chromodynamics. The approach describes the spontaneous chiral symmetry breaking and dynamical quark mass generation. Mesons appear as quark-antiquark excitations and baryons arise as non-topological solitons with three valence quarks and a polarized Dirac sea. For the evaluation of the baryon properties the present review concentrates on the non-linear Nambu-Jona-Lasinio model with quark and Goldstone degrees of freedom which is identical to the Chiral quark soliton model obtained from the instanton liquid model of the QCD vacuum. In this non-linear model, a wide variety of observables of baryons of the octet and decuplet is considered. These include, in particular, electromagnetic, axial, pseudoscalar and pion nucleon form factors and the related static properties like magnetic moments, radii and coupling constants of the nucleon as well as the mass splittings and electromagnetic form factors of hyperons. Predictions are given for the strange form factors, the scalar form factor and the tensor charge of the nucleon.

1/Nc rotational corrections to gA and isovector magnetic moment of the nucleon

The

E2M1 ratio for the γN → Δ transition in the chiral quark soliton model

1/N_c

Strange vector form factors of the nucleon in the SU(3) chiral quark-soliton model with the proper kaon cloud

rotational corrections to the axial vector constant and the isovector magnetic moment of the nucleon are studied in the Nambu -- Jona-Lasinio model. We follow a semiclassical quantization procedure in terms of path integrals in which we can include perturbatively corrections in powers of angular velocity

Nucleon described by the chiral soliton in the chiral quark soliton model

Omega sim frac 1{N_c}

Analytical continuation of the fermion determinant with a finite cut-off

. We find non-zero

Flavor asymmetry of polarized and unpolarized sea quark distributions in the large N(c) limit

1/N_c

Update of the stranger story: The strange vector form factors of the nucleon in the SU(3) chiral quark-soliton model

order corrections from both the valence and the Dirac sea quarks. These corrections are large enough to resolve the long-standing problem of a strong underestimation of both

The effects of the kaonic cloud on the neutron electric form factor

g_A

Axial form factor in the chiral quark soliton model

and