In this dissertation, I present a search for non-standard decays of a Standard Model-like Higgs boson to pairs of light bosons, as predicted in models with extended Higgs sectors. In two Higgs doublet models, including the next-to-minimal supersymmetric standard model, the Higgs boson can decay into a pair of light pseudoscalars a. In this search, the gluon fusion, W and Z associated Higgs, and vector boson fusion production channels for the Higgs are all considered, and the decay H->aa with a->[tau][tau] is reconstructed from the tau decay products. The final state is characterized by one isolated high p[subscript]T muon plus at least one highly boosted pair of taus, of which one of the taus is required to decay to a muon.Using 19.7 fb−1 of 8 TeV center of mass pp collision data recorded by the Compact Muon Solenoid experiment at the Large Hadron Collider, a counting experiment is performed in a region of high di-tau invariant mass. We have found no excess of events above the Standard Model backgrounds, and the observed data is used to set upper limits on the branching ratio Br(H->aa)Br2(a->[tau][tau]). These results are equally applicable to decays of the SM-like Higgs boson to a pair of light scalars h.

This thesis presents a study of the scalar sector in the standard model (SM), as well as various searches for an extended scalar sector in theories beyond the SM (BSM). The first part of the thesis details the search for an SM Higgs boson decaying to taus, and produced by gluon fusion, vector boson fusion, or associated production with a vector boson, leading to evidence for decays of the Higgs boson to taus. In turn, the second part highlights several searches for an extended scalar sector, with scalar boson decays to taus. In all of the analyses presented, at least one scalar boson decays to a pair of taus. The results draw on data collected by the Compact Muon Solenoid (CMS) detector during proton–proton collisions with a center-of-mass energy of 7 or 8 TeV.