New CP-odd Observable in H -> t \bar{t}

Abstract

We study a CP-violating triple product correlation that occurs in the decay of a neutral Higgs boson into t\bar{t} pairs when the Higgs boson does not have a definite CP nature. We consider the H -> t \bar{t} decay channel as well as the gluon fusion process gg -> H -> t \bar{t}. The asymmetry in Higgs decay, normalized to the H -> t \bar{t} width, can reach the 6% percent level. In the gluon fusion process the corresponding normalized asymmetry is smaller by an order of magnitude. We present a crude estimate of this observable at the LHC.

Comments: typos corrected, version to appear in Phys. Rev. D