Physicists map new strategy to hunt exotic particles at next-generation colliders

<p>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 −4/3⁢e, 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 𝑊⁢𝑏 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.</p>