$Λ_b\toΣ_c^{(*)}πl{\barν}$ in the heavy quark, chiral, and large $N_c$ limits

Abstract

The decay of $Λ_b\toΣ_c^{(*)}πl{\barν}$ processes are calculated in the framework of heavy baryon chiral perturbation theory with help of the $1/N_c$ expansion. The decay rate distributions over $v\cdot v^{\prime}$ where $v$ and $v^{\prime}$ are the 4-vector velocities of $Λ_b$ and $Σ_c^{(*)}$ respectively, and over the pion and lepton energies are given. The decay branching ratios amount to about $1.21(0.971)%$ for $Λ_b\toΣ_cπl{\barν}$ and $0.798(0.640)%$ for $Λ_b\toΣ_c^*πl{\barν}$ by using the baryonic Isgur-Wise function predicted by QCD sum rule (large $N_c$ QCD).

17 pages, 8 figures, to appear in PRD