The E6 inspired isosinglet quark and the Higgs boson

We consider the experimental implications of the down type isosinglet quark, D, predicted by the E6, group to Higgs boson searches at the LHC. The pair production of D quarks at the LHC and their subsequent decays D→hd and D→Wu has been analyzed. For a light Higgs boson of mass O(120 GeV), an analysis based on fast simulation of the ATLAS detector response shows that the bb¯ channel becomes as efficient as the γγ channel for discovering the Higgs particle if mD<630GeV.