Large $N_c$ Universality of The Baryon Isgur--Wise Form Factor: The Group Theoretical Approach

Abstract

In a previous article, it has been proved under the framework of chiral soliton model that the same Isgur--Wise form factor describes the semileptonic $Λ_b\toΛ_c$ and $Σ^{(*)}_b\toΣ^{(*)}_c$ decays in the large $N_c$ limit. It is shown here that this result is in fact independent of the chiral soliton model and is solely the consequence of the spin-flavor SU(4) symmetry which arises in the baryon sector in the large $N_c$ limit.