Bilki, Burak., ve diğer.2020-10-122020-10-122020Journal Of Hıgh Energy Physıcs,8,(139); 20201292-895Xhttps://doi.org/10.1007/JHEP08(2020)139A search for a light pseudoscalar Higgs boson (a) decaying from the 125 GeV (or a heavier) scalar Higgs boson (H) is performed using the 2016 LHC proton-proton collision data at ? s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb?1 , collected by the CMS experiment. The analysis considers gluon fusion and vector boson fusion production of the H, followed by the decay H ? aa ? µµ? ? , and considers pseudoscalar masses in the range 3.6 < ma < 21 GeV. Because of the large mass difference between the H and the a bosons and the small masses of the a boson decay products, both the µµ and the ? ? pairs have high Lorentz boost and are collimated. The ? ? reconstruction efficiency is increased by modifying the standard technique for hadronic ? lepton decay reconstruction to account for a nearby muon. No significant signal is observed. Model-independent limits are set at 95% confidence level, as a function of ma , on the branching fraction (B) for H ? aa ? µµ? ? , down to 1.5 (2.0) × 10?4 for mH = 125 (300) GeV. Model-dependent limits on B(H ? aa) are set within the context of two Higgs doublets plus singlet models, with the most stringent results obtained for Type-III models. These results extend current LHC searches for heavier a bosons that decay to resolved lepton pairs and provide the first such bounds for an H boson with a mass above 125 GeV.enBeyond Standard ModelHadron-Hadron scattering (experiments)Higgs physicsArticle10.1007/JHEP08(2020)1392-s2.0-85089987196Q3WOS:000563451600001Q3