Physical Review Letters, vol.109, no.12, 2012 (SCI-Expanded)
The dimuon invariant mass spectrum is searched in the range between 5.5 and 14GeV for a light pseudoscalar Higgs boson a, predicted in a number of new physics models, including the next-to-minimal supersymmetric standard model. The data sample used in the search corresponds to an integrated luminosity of 1.3fb-1 collected in pp collisions at √s=7TeV with the CMS detector at the LHC. No excess is observed above the background predictions and upper limits are set on the cross section times branching fraction σ×B(pp→a→μ+μ-) in the range of 1.5-7.5pb. These results improve on existing bounds on the abb̄ coupling for ma