Recently, Dashen and Manohar have derived a set of consistency conditions that must be satisfied by large-N(c) QCD, which enables them to give quite a general proof to that some of the large-N(c) spin-flavor symmetry relations for baryon observables are violated only at order 1/N(c)2. We try to clarify not only the power but also the limitation of their model-independent approach through a comparative analysis of 1/N(c) corrections to baryon observables in three simple effective models of QCD. We then advocate a viewpoint that the N(c) --> infinity limit and the 1/N(c) expansion framework should be clearly distinguished, because the former has little to do with our real world.
机构:
St Petersburg State Univ, Dept High Energy Phys, St Petersburg 198904, RussiaSt Petersburg State Univ, Dept High Energy Phys, St Petersburg 198904, Russia