Single vector-like quark X production in the tW channel at high energy pp colliders

Vector-like quarks (VLQs) are color-triplet spin-1/2 fermions whose left- and right-handed chiral components have the same transformation properties under the weak-isospin SU(2) gauge group. The X vector-like particle with a charge of |Q|=+5/3 exists in the (X,T) doublet or (X,T,B) triplet states. Based on a simplified model, we investigate the prospect of discovering the doublet right-handed X via the single production of X followed by X→tW at the 14 TeV High Luminosity LHC (HL-LHC), 27 TeV High Energy LHC (HE-LHC), and 100 TeV hadron-hadron Future Circular Hadron Collider (FCC-hh). We perform a detailed detector simulation, and find that the excluding and discovering capabilities on the X quark are enhanced obviously with the increase of collision energy. Assuming the system uncertainty is 30% of the number of the background events, the excluding capabilities are given as follows: (1) the HL-LHC can exclude the correlated regions of the mixing constant sin⁡θR∈0.082,0.2 and the X quark mass mX ∈ 1000 GeV, 1680 GeV with L=3 ab−1; (2) the HE-LHC can exclude the correlated regions of sin⁡θR∈0.067,0.2 and mX ∈ 1000 GeV, 2230 GeV with L=15 ab−1; (3) the FCC-hh can exclude the correlated regions of sin⁡θR∈0.078,0.2 and mX ∈ 1000 GeV, 2560 GeV with L=30 ab−1.