RESUMEN
We introduce a modification to the standard expression for tree-level CP violation in scattering processes at the LHC, which is important when the initial state is not self-conjugate. Based on that, we propose a generic and model-independent search strategy for probing tree-level CP violation in inclusive multilepton signals. We then use TeV-scale 4-fermion operators of the form tuââ and tcââ with complex Wilson coefficients as an illustrative example and show that it may generate O(10%) CP asymmetries that should be accessible at the LHC with an integrated luminosity of O(1000) fb^{-1}.
RESUMEN
Present limits on chiral fourth-generation quark masses mb' and mt' are broadly generalized and strengthened by combining both t' and b' decays and considering a full range of t' and b' flavor-mixing scenarios with the lighter generations (to 1-âV44â2≈10(-13)). Various characteristic mass-splitting choices are considered. With mt'>mb' we find that CDF Collaboration limits on the b' mass vary by no more than 10%-20% with any choice of flavor mixing, while for the t' mass, we typically find stronger bounds, in some cases up to mt'>430 GeV. For mb'>mt', we find mb'>380-430 GeV, depending on the flavor mixing and the size of the mt'-mb' mass splitting.