Exotic decays of top partners with charge 5/3: bounds and opportunities

Abstract

Abstract Exotic decays of top partners in new bosons are the norm in realistic models of a composite Higgs. We focus on the custodial charge-5/3 partner, which normally decays exclusively into tW +. The new channels include a colour-sextet, X 5/3 → b ¯ $$ \overline{b} $$ π 6, as well as singly and doubly charged scalars, X 5/3 → t𝜙+, b𝜙++. We use existing same-sign lepton searches to show that the new final states are constrained at the same level as the standard one. At the same time, exotic final states also offer opportunities for improvement: examples include a hard photon in X 5/3 → t𝜙+ → tW + γ decays, and top-rich channels which arises in several exotic X 5/3 decays.

Keywords

• Exotics
• vector-like quarks
• Beyond Standard Model
• Hadron-Hadron scattering (experiments)
• same charge top pair