Λb → Σ (∗) c πlν¯ in the heavy quark, chiral, and large Nc limits

摘要: The decay of Λb → Σ(∗)c πlν¯ processes are calculated in the framework of heavy baryon chiral perturbation theory with help of the 1/Nc expansion. The decay rate distributions over v · v′ where v and v′ are the 4-vector velocities of Λb 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 Λb → Σcπlν¯and 0.798(0.640)% for Λb → Σ∗cπlν¯ by using the baryonic Isgur-Wise function predicted by QCD sum rule (large Nc QCD).