Signatures of Higgs Bosons in the Top Quark Decay Channel at Hadron Colliders

We analyze some signatures of neutral Higgs bosons, produced in high energy proton (anti)proton collisions, which decay primarily to top quarks. This channel is clouded by a large irreducible $t\bar{t}$ background. We investigate the $t\bar{t}$ invariant-mass distribution in the lepton+jets decay mode of $t\bar{t}$ and a $t\bar{t}$ spin-spin correlation in the dilepton decay mode. At the LHC such Higgs bosons can be detected in the $t\bar{t}$ invariant-mass spectrum, and the spin-spin correlation studied by us is also sensitive to a Higgs boson if this particle has a sizeable pseudoscalar component.