It is still an open question whether the new scalar particle discovered at
the LHC with a mass of 125 GeV is the SM Higgs boson or it belongs to models of
new physics with an extended Higgs sector, as the MSSM or 2HDM. The ratio of
branching fractions R = BR(H→bbˉ)/BR(H→τ+τ−) of
Higgs boson decays is a powerful tool in order to distinguish the MSSM Higgs
sector from the SM or non-supersymmetric 2HDM. This ratio receives large
renormalization-scheme independent radiative corrections in supersymmetric
models at large tanβ, which are insensitive to the SUSY mass scale and
absent in the SM or 2HDM. Making use of the current LHC data and the upcoming
new results on Higgs couplings to be reported by ATLAS and CMS collaborations
and in a future linear collider, we develop a detailed and updated study of
this ratio R which improves previous analyses and sets the level of accuracy
needed to discriminate between models.Comment: 11 pages, 3 figures, 1 tabl