New universality of the baryon Isgur-Wise form factor in the largeNclimit

New universality appears for the baryon Isgur-Wise form factor in the large ${\mathit{N}}_{\mathit{c}}$ limit. It is found that the semileptonic ${\mathrm{\Lambda }}_{\mathit{b}}$→${\mathrm{\Lambda }}_{\mathit{c}}$ and ${\mathrm{\Sigma }}_{\mathit{b}}^{\left(\mathrm{*}\right)}$→${\mathrm{\Sigma }}_{\mathit{c}}^{\left(\mathrm{*}\right)}$ decays are described by the same form factor, which can be calculated analytically. In the exact chiral SU(3) limit, the same form factor is applicable to semileptonic ${\mathrm{\Omega }}_{\mathit{b}}^{\left(\mathrm{*}\right)}$→${\mathrm{\Omega }}_{\mathit{c}}^{\left(\mathrm{*}\right)}$ decays.