Even-wave harmonic-oscillator theory of baryonic states. V. Polarized photoproduction of single pions

Abstract

A variant of the harmonic-oscillator (h.o.) model, termed the even-wave h.o. model (with quarks having h.o. interaction in even waves only), which was developed by Mitra and co-workers in a series of recent papers, is applied to the phenomenon of polarized photoproduction. The model, which predicts a ground state of (70,0⁺) and assumes an 8d mixing angle (cotθ =√2) between 56 and 70 states, was recently found to give a good account of (i) the mass spectra of resonances, (ii) low-energy parameters such as G_A/G_V, Δ→Nπ width, and NNπ coupling constant, and (iii) resonance photocouplings, with no free parameters other than a universal spring constant (Ω≈1 GeV²). The present investigation reveals that this model agrees better with the data on polarized-target asymmetry as well as dσ_|| and d⊥_Φ than does the conventional h.o. model.