Inelastic Meson-Baryon Scattering with Veneziano Model andSU(3) Symmetry

Abstract

Inelastic meson baryon scattering of the type o- + t + ~o- + t + is studied on the basis of Veneziano model for some of the reactions and exact SU(3) symmetry. The differential cross section in the forward direction is found to be in agreement with the available data. The f/d ratios for the octets 1- and 2+ are found to be -6.0 and 0.67, respectively. § I. Introduction The conventional Regge pole phenomenology of the high energy reactions requires the specification of residue functions associated with the· Regge poles. Although most processes have been parametrized in terms of Regge poles, satis­ factory residue functions do not exist for any process whatsoever. The Veneziano form offers the possibility of obtaining from a single expression the description of both the low energy resonance parameters and the Regge pole residue in the appropriate high energy limits. Previous studies 1 > on scattering between meson and spin t baryons were made on the basis of Regge pole+ SU(3) symmetry. These studies present a fit to the experimental information regarding the energy and angular dependence of the cross section, the baryon polarization for elastic charge exchange, sharp forward peaks in differential cross section and in a number of reactions, secondary maxima following the forward peak. Reeder and Sarma's detailed analysis of charge ex­ change and hypercharge exchange reactions has, besides fitting all the available data . at -t>I(GeV/cY, the following relative merits: (a) the Reggeization of the heli­ city amplitudes free from kinematical singularities, (b) the insertion of a zero in the non-flip amplitude G++ (p) to account for the cross-over effect, (c) allow­ ing the scale factor as an arbitrary parameter to be fitted from the data, (d) al­ lowing for the possible curvature of the trajectories, (e) treatment of statistical and normalization errors, (f) SU (3) symmetry for the factorized residues to de­ termine f/ d ratios for the vector and tensor JP = t + baryon couplings. This model failed to account for (a) the observed peaking in the angular distribution, (b) the dip position which could, of course, be shifted by adding s-channel isobar effects, (c) the observed polarization. The general features of the available data on differential cross section were, however, reproduced. Also, the value of (f/d)v was a factor of 3 larger than the corresponding value determined from the Regge