  A search is reported for a light pseudoscalar Higgs boson decaying to a pair
of tau leptons, produced in association with a b b-bar pair, in the context of
two-Higgs-doublet models. The results are based on pp collision data at a
centre-of-mass energy of 8 TeV collected by the CMS experiment at the LHC and
corresponding to an integrated luminosity of 19.7 inverse femtobarns.
Pseudoscalar boson masses between 25 and 80 GeV are probed. No evidence for a
pseudoscalar boson is found and upper limits are set on the production cross
section times branching fraction to tau pairs between 7 and 39 pb at the 95%
confidence level. This excludes pseudoscalar A bosons with masses between 25
and 80 GeV, with standard model-like Higgs boson negative couplings to
down-type fermions, produced in association with b b-bar pairs, in Type-II,
two-Higgs-doublet models.
