Two body non-leptonic ${\mathrm{\Lambda }}_b$ decays in the large $N_c$ limit

The two body non-leptonic ${\mathrm{\Lambda }}_b$ decays are analyzed in the HQET with factorization approximation and large $N_c$ limit. In this limit, ${\mathrm{\Lambda }}_b$ and ${\mathrm{\Lambda }}_c$ baryons can be treated as the bound states of chiral soliton and heavy meson, and consequently the Isgur-Wise function comes out in a straight forward manner. The results obtained remain well below their previously predicted upper limit.