Tuning CP-odd observables to resolve the sign ambiguity between scalar and pseudo-scalar top-Higgs couplings in ttH production at the LHC

NICOLÁS MILEO; ERNESTO ARGANDA; DANIEL ALBERTO DÍAZ; ALEJANDRO ANDRÉS SZYNKMAN

Sao Paulo

Simposio; First Joint ICTP-Trieste/ICTP-SAIFR School on Particle Physics; 2018

ICTP-SAIFR

In the present study, we consider the hypothesis proposed in previous works of a top-Higgs coupling which differs from the CP-even Standard Model case in the addition of a CP-odd term. The pseudoscalar top-Higgs coupling can be tested in a direct way by measuring the process pp ttH which occurs with a very low cross section at the LHC. Therefore, it is crucial to define observables capable to resolve the sign ambiguity in order to probe it with a number of events consistent with the short-term expectations for the LHC. We present a set of CP-odd observables which are more sensitive to the relative sign between the scalar and pseudoscalar couplings than others proposed in the current bibliography and also discuss different approaches which may help to improve the discriminating power.