摘要:

AbstractThree different types of relations for meson‐baryon partial wave amplitudes following from thes↔ucrossing symmetry of the invariant amplitudes are investigated: i) the partial wave crossing relations directly derived from thes↔ucrossing symmetry and the partial wave projection, ii) the partial wave crossing relations following from a combined use ofs↔ucrossing symmetry and analyticity, and iii) the crossing sum rules, which are a direct consequence of thes↔ucrossing symmetry.The kernels entering the crossing relations i) and ii) are given in an analytic form, valid for arbitrary angular momentum. Their properties are studied in detail. By means of the partial wave crossing relations ii) it is demonstrated thatu‐channel exchange of a resonance leads to a resonance‐like behaviour of the partial wave amplitudes on the crossed physical cut. This phenomenon is described in terms of “pseudoresonances”. Finally the crossing sum rules iii) and their practical use are thoroughly discussed, and they are compared with the partial wave crossing relations i) and ii).Special attention is paid to the crossing symmetry constraints on theS‐wave amplitudes. As a result of these investigations we present a crossing symmetric ansatz for these amplitudes which gives a more reliable parametrization than the usual effective

ISSN:0015-8208    

DOI:10.1002/prop.19710190302

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0015-8208    

DOI:10.1002/prop.19710190301

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY