Add Lb_LcDsst decfile
New dec file for measuring \Lambda_c^+D_s^- invariant mass dependent efficiencies of the partially reconstructed \Lambda_b^0\to\Lambda_c^+D_s^{\ast-} decays.
New dec file for measuring \Lambda_c^+D_s^- invariant mass dependent efficiencies of the partially reconstructed \Lambda_b^0\to\Lambda_c^+D_s^{\ast-} decays.