Search for a low-mass pseudoscalar Higgs boson produced in association with a pair of b-quarks and decaying to tau leptons at CMS

A search is reported for a light pseudoscalar A boson decaying to a pair of tau leptons, produced in association with a pair of b quarks, in the context of two-Higgs-doublet models. The results are based on pp collision data at a centre-of-mass energy of s = sqrt(8) TeV accumulated by the CMS experiment at the LHC and corresponding to an integrated luminosity of 19.7 fb$^{-1}$. Pseudoscalar A boson masses are probed between 25 and 80 GeV and upper limits are set on the production cross section times branching fraction to tau pairs between 7 and 39 pb at the 95pct confidence level. For masses below 80 GeV, this search excludes the pseudoscalar A boson in Type 2 two-Higgs-doublet models with negative Yukawa coupling to down-type fermions.