The Role of the $t{\bar t}h$ Rest Frame in Direct Top-Quark Yukawa Coupling Measurements

Understand

This paper studies new possibilities to directly measure a hypothetical $CP$-odd (pseudoscalar) component in the top-quark Yukawa coupling.

• In particular, the role of the $t{\bar t} h$ center-of-mass rest frame in the associated production of a top pair and a $h$ boson at the LHC is explored.
• The $h$ boson is assumed to have both a $CP$-even (scalar) and a $CP$-odd coupling to the top quark.
• The relative strength of the scalar and pseudoscalar components is regulated by an angle $\alpha$.