Single production of an exotic vectorlike Y quark at future high energy pp colliders

Vectorlike quarks have been predicted in various new physics scenarios beyond the Standard Model. In a simplified modelling of a (B,Y) doublet including a vectorlike quark Y, with charge −43e, there are only two free parameters: the Y coupling κY and mass mY. In the five flavor scheme, we investigate the single production of the Y state decaying into Wb at the Large Hadron Collider (LHC) run-III and High-Luminosity LHC (HL-LHC) operating at s=14 TeV, the possible High-Energy LHC (HE-LHC) with s=27 TeV as well as the Future Circular Collider in hadron-hadron mode (FCC-hh) with s=100 TeV. Through detailed signal-to-background analyses and detector simulations, we assess the exclusion capabilities of the Y state at the different colliders. We find that this can be improved significantly with increasing collision energy, especially at the HE-LHC and FCC-hh, both demonstrating an obvious advantage with respect to the HL-LHC in the case of high mY. Assuming a 10% systematic uncertainty on the background event rate, the exclusion capabilities are summarized as follows: (1) the LHC run-III can exclude the correlated regions of κY∈0.06,0.5 and mY∈1500 GeV,3800 GeV with integrated luminosity L=300 fb−1; (2) the HL-LHC can exclude the correlated regions of κY∈0.05,0.5 and mY∈1500 GeV,3970 GeV with L=3 ab−1; (3) the HE-LHC can exclude the correlated regions of κY∈0.06,0.5 and mY∈1500 GeV,6090 GeV with L=3 ab−1; (4) the FCC-hh can exclude the correlated regions of κY∈0.08,0.5 and mY∈1500 GeV,10080 GeV with L=3 ab−1. Published by the American Physical Society 2024