Interference Effects in $t{\bar t}$ Production at the LHC as a Window on New Physics

Understand

Many extensions of the Standard Model contain (pseudo)scalar bosons with masses in the TeV range.

• At hadron colliders, such particles would predominantly be produced in gluon fusion and would decay into top quark pair final sates, a signal that interferes with the large QCD background $gg \to t\bar t$.
• This phenomenon is of interest for searches for by the LHC experiments.
• Here, we consider the signal and background interference in this process and study it in various benchmark scenarios, including models with extra singlet (pseudo)scalar resonances, two-Higgs doublet models, and the minimal supersymmetric extension of the SM with parameters chosen to obtain the measured light Higgs mass (the hMSSM).