ISGUR-WISE FORM-FACTORS OF HEAVY BARYONS WITHIN A LIGHT-FRONT CONSTITUENT QUARK-MODEL

The space-like elastic form factors of baryons containing a heavy quar k are investigated within a light-front constituent quark model in the limit of infinite harvy-quark mass, adopting a gaussian-like ansatz f or the three-quark wave function. The results obtained for the Isgur-W ise form factors corresponding both to a spin-0 and a spin-1 light spe ctator pair are presented. It is found that the Isgur-Wise functions d epend strongly on the baryon structure, being sharply different in cas e of diquark-like or collinear-type configurations in the three-quark system. It is also shown that the relativistic effects lead to a satur ation property of the form factors as a function of the baryon size. O ur results are compared with those of different models as well as with recent predictions from QCD sum rules and lattice QCD simulations; th e latter ones seem to suggest the dominance of collinear-type configur ations, in which the heavy-quark is sitting close to the center-of-mas s of the Light quark pair. (C) 1998 Elsevier Science B.V.