Axial amplitudes for Δ excitation in chiral quark models (original) (raw)

We study the axial amplitudes for the N-∆ transition in models with quarks and chiral mesons. A set of constraints on the pion field is imposed which enforces PCAC and the off-diagonal Goldberger-Treiman relation. The quark contribution to the amplitudes in general strongly underestimates the C A 5 amplitude as well as the πN∆ strong coupling constant. We show that the results are considerably improved in models that, in addition to the pion cloud, incorporate a fluctuating σ field inside the baryon.