A recently proposed model (MM) of higher baryon couplings for P and V mesons is reformulated by reviewing the fuller possibilities of the "recoil term" in the primitive quark-meson interaction. While this introduces no basic change in the P-meson coupling structures, it yields an entirely new (L -1)-wave coupling of V mesons to J = L + i baryons, which is capable of generating helicity-flip amplitudes. The advantage of this new coupling structure over the earlier one is demonstrated through the excellent reproduction of (i) the E l angular distribution in Y*-Ay decay and (ii) the appreciable magnitudes as well as energy variations of the asymmetry parameter 2 ( 0 ) in pion photoproduction. In addition to a comparison of the two coupling structures (old and new), the present paper is also designed to study the role of still another parametric structure for the form factor -one which exhibits better convergence properties at higher energies than those discussed in MM. The additional processes studied in this connection a r e (i) 17 andX,, photoproduction at intermediate energies ( > 2 GeV), (ii) polarization of the recoil proton in 17 and n photoproduction, and (iii) no photoproduction at high energies ( -6 GeV), in accordance with our earlier scheme of s-channel resonances. In connection with 17 photoproduction the roles of some pertinent 1 = 4 resonances such as St,, P I , ,and G i7 a r e discussed, especially in relation to supermultiplet assignments.
I . INTRODUCTIONRecently, a general relativistic coupling scheme'*2 was suggested by one of us (A.N.M.) for baryon resonances (B,), which in turn a r e classified according to the (56,2L+) and ( 7 0 , ( 2~ + I)-) representation of SU(6) x 0(3).3 In thismodel, the coupling structures a r e of the multiple-derivative type connecting Dirac fields with generalized Rarita-Schwinger fields, and the geometrical factors multiplying the various coupling terms correspond to certain form factors for each supermultiplet transition and a r e given suitable parametriz a t i o n~ so a s to conform to a set of general req u i r e m e n t~.~ So far, three different types of form factors5 have been suggested within this framework, so a s to satisfy the above "requirements" in varying degrees, keeping in mind the fits to observed decay patterns. We shall refer to these form factors a s I, ' and 111,' in the chronological order of their introduction. One seeks to connect the structures of the BB,P and BB,V couplings in all these cases via the requirement of partial symmetry ora a chiral SU(3) x SU(3) at the level of ~M Q (M =P, V) interactions. Two recent applications of this formalism to several aspects of the processes yN-nN7 and ?rN-pN,' which have been made with I and 11, show that they can indeed fit the data quite well, 11 giving a somewhat better fit than I. Since the general formalism has been worked out in sufficient detail in these two papers, we shall refer to them as MM7 and SG,8 respectively, and make free use of their results.The above coupling scheme, which i s fairly...