Model independent calculation of B(anti B0→D(*)+τ- anti ν)/B(anti B0→D(*)+e- anti ν)

Using the formulas for the dΓ/dq2 distribution with non-zero lepton mass and experimentally determined form factors, we calculate the dΓ(D(*)+l- anti ν)/dq2 spectra and branching fractions for l=e,μ and τ. We obtain the results B(anti B0→D+τ- anti ν)/B(anti B0→D+e- anti ν)=0.278+0.049-0.035 and B(anti B0→D*+τ- anti ν)/B(anti B0→D*+ e- anti ν)=0.256+0.014-0.013. Since we used the experimentally measured form factors, these results are independent of theoretical models of the form factors. (orig.)