Baryons as solitons in the effective Lagrangian of spontaneously broken chiral symmetry

Lai Him Chan, Louisiana State University


I present the calculation of the effective Lagrangian from the σ quark model based on some reasonable assumptions of the spontaneously broken chiral symmetry, the large-Nc limit, and the nature of the effective action expansion. In addition to the Skyrme Lagrangian with a unique coupling constant e=π[2(3/Nc)]1/2 and the Wess-Zumino term, it contains an extra new term (Nc/96π2) Tr (μLμ)2 which must be treated as a perturbative correction. This new term is responsible for the correct pion form factor corresponding to mρ2=8π2fπ2(3/Nc). This model can be used to describe the rich low-energy dynamics of baryons and mesons with the unique mass scale fπ. © 1985 The American Physical Society.