Speaker
Prof.
Emidio Gabrielli
(University of Trieste and NICPB Tallinn)
Description
We compare the impact of top-quark spin polarization effects in Higgs (H) boson production in association with top-quark pairs and in corresponding backgrounds at the LHC. Because of the spin-zero nature of the Higgs boson, one expects, in the chiral limit for the top quarks, a substantial complementarity in tt(bar) spin correlations for a Higgs decaying into fermions/gauge-bosons and tt(bar) spin correlations for the corresponding irreducible tt(bar)ff(bar)/VV backgrounds. Although top mass effects in tt(bar)H production are in general dominant, and seriously spoil the chiral-limit expectations, one can find observables that capture the tt(bar) angular spin correlations and can help in separating the signal from irreducible backgrounds. In particular, we show that, for both H→bb(bar) and H→gamma-gamma, taking into account tt(bar) spin correlations in tt(bar)H production and irreducible backgrounds could appreciably improve the LHC sensitivity to the tt(bar)H channel.
Primary author
Prof.
Emidio Gabrielli
(University of Trieste and NICPB Tallinn)