High Level Trigger for the tt¯H channel in fully hadronic decay at LHC with the CMS detector

One of the most promising channels to discover a “light” Higgs boson (mass of 120−130GeV/c2) with the CMS detector at LHC is the tt¯H channel. In this study we investigate the possibility of selecting this channel from the QCD multijets background. We present a High Level Trigger selection for the tt¯H decaying in fully hadronic final states. The basic idea is to use a fast b-tagging algorithm after the Level-1 trigger selection based on the number of jets and energy cuts. The main background source considered is direct QCD multijet production with pile up at low luminosity (2×1033cm−2s−1) scenario.