The Phenomenology Of Vector-like Bottom Quark At High Energy Colliders

The standard model(SM)of particle physics successfully describes the strong,the weak and the electromagnetic interactions,and has been precisely tested by the experiments in the past decades years.The discovery of a 125 GeV Higgs bosson in July 2012 announced by the ATLAS and CMS collaborations at the CERN Large Hadron Collider(LHC),which completed the last piece of the elementary particles of the SM.Despite the SM has acquired remarkably success,it has unresolved theoretical issues,such as too much free parameters,the hierarchy between the electroweak and the Planck scales and so on.To solve these problems,various new physics models beyond the SM at a higher scale are proposed.As a class of interesting new particles that are hypothetical spin -1/2 colored fermions,vector-like quarks(VLQs)which regulate the Higgs boson mass-squared divergence are pre-dicted in many new physics scenarios,i.e.little Higgs models,composite Higgs models and some extra-dimension models.VLQs can obtain the direct gauge invariant mass term of the form (?).This means that VLQs are not subject to the constraints from Higgs production and not excluded by precision measurements.The left-and right-handed components of VLQs have the same transformation properties under the SM electroweak symmetry group.The weak hy-percharges of VLQs can be determined by their Yukawa couplings with the SM quarks and the Higgs boson,therefore there are four possible charge assignments:(?),and(?),which might appear in SU(2)singlets or multiplets.In this paper,we study the possibility of detecting the vector-like bottom quark(VLQ-B)being the SU(2)singlet with electric charge-1/3 at LHC and LHeC in a model-independent framework.Through a generic parametrization of an effective Lagrangian approach,we brief review the couplings of VLQ-B with the SM particles,and discuss its possible decay modes.The decay properties and single production of VLQ-B at the LHC/LHeC are explored.By carrying out a fast simulation for the signals and the corresponding backgrounds,the signal significances are obtained.Through the process (?) at the LHC,we discuss the required parameter space by detecting the VLQ-B with electric charge of (?),which is the SU(2)singlet.Similarly,for the detecting of VLQ-B at the LHe C,we find that the possible signatures of the SU(2)singlet VLQ-B with electric charge -1/3 is easier detected via the process (?) in the semileptonic channel than the fully leptonic channel or the fully hadronic channel.