Search for the pseudoscalar Higgs boson A 0 of the bestest little Higgs model at the LHC and FCC-hh

We analyze the sensitivity of the Large Hadron Collider (LHC) and the Future Circular Collider-hadron-hadron (FCC-hh) to the existence of pseudoscalar Higgs boson A 0 predicted by the bestest little Higgs model. We study the tree-level (two and three body) and one-loop decays of the pseudoscalar, A 0 → b b ¯ , t t ¯ , γ t t ¯ , γ b b ¯ , Z t t ¯ , Z b b ¯ , W t b ¯ , h 0 t t ¯ , h 0 b b ¯ , and A 0 → γ γ , γ Z , Z Z , g g , W W , respectively. In addition, we perform a phenomenological study of the production of the pseudoscalar A 0 via gluon-fusion g g → A 0 → Y processes, where Y ≡ b b ¯ , t t ¯ , γ γ , γ Z , Z Z , g g , W W . From the cross section of the processes of interest and the expected integrated luminosity of the LHC and FCC-hh, we determined the number of events that could be produced in both colliders.