A lattice study of Λ_b semileptonic decay

We present results from a lattice study of the semileptonic decay $\Lambda_b \to \Lambda_c l \nu_l $. We use $O(a^2, \alpha_s a^2)$ improved quenched lattices of the MILC collaboration, with lattice spacing $\sim 0.13$ fm. For the valence quarks, the tadpole-improved clover action is used, with the Fermilab method employed for the heavy quarks. Form factors are extracted from the vector as well as the axial-vector part of the current.