The method to determine the CP nature of Higgs bosons from decays to tau leptons at LC

Abstract

We demonstrate how the transverse tau tau spin correlations can be used to determine whether a decaying Higgs boson is a mixed CP eigenstate, thereby directly probe the presence of CP violation in the neutral Higgs boson sector. We investigate the subsequent decay chain H --> tau+ tau- --> rho+ nu rho- nu --> pi+ pi0 nu pi- pi0 nu. The prospects for the measurement of the pseudoscalar admixture in the H-tau-tau coupling to a Standard Model Higgs boson with a mass of 120 GeV are quantified for the case of e+e- collisions at 350 GeV center-of-mass energy and 1 ab^{-1} integrated luminosity. The Standard Model Higgsstrahlung production process is used as an example.