Search For A Very Light Nmssm Higgs Boson Produced In Decays Of The 125 Gev Scalar Boson And Decaying Into Tau Leptons In Pp Collisions At The Lhc

A search for a very light Higgs boson decaying into a pair of tau leptons is presented within the framework of the next-to-minimal supersymmetric standard model(NMSSM). This search is based on a data set corresponding to an integrated luminosity of 19.7 fb-1 and 2.5 fb-1 of proton-proton collisions collected by the CMS experiment at a centre-of-mass energy of 8 TeV and 13 TeV respectively. The signal consists of the production of either of the two lightest scalars, h1 or h2, via gluon-gluon fusion and subsequent decay into a pair of the lightest Higgs bosons, a1 or h1. The h1 or h2 boson is identified with the observed state at a mass of 125 GeV. The analysis searches for decays of the a1(h1) states into pairs of tau leptons and covers a mass range for the a1(h1) boson of 4 to 15 GeV. The search reveals no significant excess in data above standard model background expectations, and an upper limit is set on the signal production cross section times branching fraction as a function of the a 1(h1) boson mass.