Lattice measurement of the Isgur-Wise functions τ1/2 and τ3/2

We propose a method to compute the Isgur-Wise form factors τ1/2(1) and τ3/2(1) for the decay of B mesons into orbitally excited (P wave) D** charmed mesons on the lattice in the static limit. We also present the result of a quenched exploratory numerical simulation which shows that the signal/noise ratio allows for a more dedicated computation.