29 May 2007 to 4 June 2007
DESY Hamburg
Europe/Zurich timezone

CP properties of the Higgs boson via ttbar Higgs

1 Jun 2007, 09:50
25m
SemRm FLA (DESY Hamburg)

SemRm FLA

DESY Hamburg

Notkestraße 85 22607 Hamburg Germany

Speaker

Prof. Rohini Godbole (IISC Bangalore)

Description

We analyse the associated production of the Higgs boson with a top quar pair, ${e^-e^+ \to t\bar t\Phi}$, in the most general case where the coupling is a mixture of scalar and pseudoscalar components, $g_{\Phi t \bar t} \propto (a+i b \gamma_5)$. We have calculated the individual helicity amplitudes for the process and obtained the corresponding cross sections for each helicity state; we have also constructed the top quark polarization asymmetries with polarized and unpolarized initial $e^\pm$ beams. The sensitivity of the pseudoscalar component of the coupling $b$ to the cross section and polarization asymmetry has been investigated. We find that although neither of these observables is very sensitive to the parameter $b$ except for values close to unity, both can clearly distinguish a purely CP--even Higgs state from a purely CP--odd state. Finally, we have constructed an up--down asymmetry for the produced top quark which allows to probe the CP mixing of the Higgs state $\Phi$.

Primary author

Prof. Rohini Godbole (IISC Bangalore)

Presentation materials