Determining the CP properties of the Higgs boson

TL;DR

It is demonstrated that the CP properties of a standard model-like Higgs particle can be unambiguously assessed by measuring just the total cross section and the top polarization in associated Higgs boson production with top quark pairs in e(+)e(-) collisions.

Abstract

The search and the probe of the fundamental properties of Higgs boson(s) and, in particular, the determination of their charge conjugation and parity (CP) quantum numbers, is one of the main tasks of future high-energy colliders. We demonstrate that the CP properties of a Standard Model-like Higgs particle can be unambiguously assessed by measuring just the total cross section and the top polarization in associated Higgs production with top quark pairs in e+e- collisions.

Figures (4)

• Figure 1: Feynman diagrams for the associated production of Higgs bosons with a top quark pair.
• Figure 2: The production cross sections $\sigma(e^+e^- \to t\bar{t} \Phi)$ for a scalar and a pseudoscalar Higgs boson as a function of $\sqrt s$ for two masses $M_\Phi=120$ and 150 GeV (left) and for unpolarized and polarized $e^\pm$ beams as a function of the parameter $b$ at $\sqrt s=800$ GeV with $M_\Phi=120$ GeV (right).
• Figure 3: The top quark polarization in the process $e^+e^- \to t\bar{t} \Phi$ for a scalar and a pseudoscalar Higgs boson as a function of $\sqrt s$ for two masses $M_\Phi=120$ and 150 GeV (left) and with unpolarized and polarized $e^\pm$ beams as a function of the parameter $b$ at $\sqrt s=800$ GeV for $M_\Phi=120$ GeV (right).
• Figure 4: The sensitivity of the cross section (left) and the top quark polarization (right) on the parameter $b$ for $M_\Phi=120$ at $\sqrt s=800$ with ${\cal L}=500$ fb$^{-1}$.