Search for vector -like T quark through th channel at e? collider

In an extension of the Standard Model with vector-like top partner, we investigate the vector-like top quark partner T via the channel e−γ→bνeT¯(→t¯h) at future linear collider. Due to the larger production rates than unpolarized beams, we calculate the production cross sections in polarized beams at s=2 and 3 TeV. We make a fast detector simulation for signal and background events and take a set of appropriate kinematic variables to enhance the signal significance. When the initial state radiation and beamstrahlung effects are in charge, we find that the correlated region g⁎∈[0.33,0.5] ([0.14,0.5]) and mT∈[1300GeV,1480GeV] ([1300GeV,1900GeV]) can be excluded at 2σ level with the integrated luminosity 600fb−1 (3000fb−1) at s=2 TeV. When the center-mass energy s is upgraded to 3 TeV, the excluded region is expanded to g⁎∈[0.3,0.5] ([0.14,0.5]) and mT∈[1300GeV,1940GeV] ([1300GeV,2000GeV]) with the integrated luminosity 600fb−1 (3000fb−1). Besides, we find the 5σ discovery correlated region is g⁎∈[0.30,0.5] ([0.27,0.5]) and mT∈[1300GeV,1500GeV] ([1300GeV,2000GeV]) with the integrated luminosity 3000fb−1 at s=2 TeV (3 TeV). © 2020 The Author(s)