Strong phase at colliders--new physics opportunities for ttbar resonance searches and Higgs physics searches
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In this talk I will present several interesting physics cases where the strong phase from QCD plays important role in (B)SM heavy particle productions at hadron colliders. The strong phase in these cases does alter the resonance signatures a lot and provide more physics insights to the underlying physics. The heavy scalar resonance search channel of gg→S→tt is very challenging due to a large destructive interference with the SM background. We analyze the line shapes of heavy scalars in several well-motivated beyond the standard model physics models. Commonly existing additional contributions to the glu-glu-scalar coupling change the relative phases of the signal and background amplitudes, inducing new opportunities in this channel. We further outline various methods to improve the LHC search in this channel. The strong phase also plays important role in some Higgs searches channels that have long been overlooked, and I will discuss the corresponding phenomenology and the new window opened up for BSM physics.