THE e e Z l l bb + − − + → →  COLLISION IN THE RANDALL-SUNDRUM MODEL

Taking account of the Randall-Sundrum model, we have evaluated the influence of model parameters in e e Z l l bb + − − + → →  collision at International Linear Colliders (ILC). In the ILC region, the total cross-section is enhanced at the 125 GeV radion. The total cross-section depends on the polarization of e e − + , initial beams, the radion mass m , the center of mass energy s . Based on the forward - backward asymmetry and the polarization of beams, the reaction can give observable cross-sections based on l l bb − + final state.

Search for single production of vector-like B quark decaying to bZ at future linear colliders

New vector-like quarks are predicted in many new physics scenarios beyond the Standard Model (SM). Based on a model-independent framework, we investigate the prospect of discovering the SU(2) singlet vector-like bottom quark (VLQ-B) in $$e^{+}e^{-}$$ e + e - collisions at 3 TeV Compact Linear Collider. We study the single VLQ-B production process $$e^{-}e^{+}\rightarrow B{\bar{b}}\rightarrow Zb{\bar{b}}$$ e - e + → B b ¯ → Z b b ¯ with two types of decay channel: $$Z\rightarrow \ell ^{+}\ell ^{-}$$ Z → ℓ + ℓ - , and $$Z\rightarrow \nu {\bar{\nu }}$$ Z → ν ν ¯ . By carrying out a full simulation for the signals and the relevant SM backgrounds, the $$2\sigma $$ 2 σ exclusion limit and $$5\sigma $$ 5 σ discovery prospects are, respectively, obtained on the B quark mass and the coupling strength $$g^{*}$$ g ∗ with the integrated luminosity of 5 $$\hbox {ab}^{-1}$$ ab - 1 . Our numerical results show that the possible signals of the singlet VLQ-B might be detected at the future high-energy $$e^{+}e^{-}$$ e + e - linear colliders.

Dijet production in generic contact interaction at linear colliders

We consider dijet production at a e+e− collider in a class of effective theories with the relevant operators being four-fermion contact interaction. Despite the nonrenormalizable nature of the interaction, we explicitly demonstrate that calculating QCD corrections is both possible and meaningful. Calculating the corrections for various differential distributions, we show that these can be substantial and significantly different from those within the SM. Furthermore, the corrections have a very distinctive flavor dependence.

The influence of the scalar unparticle on the W-pair production at ILC in the Randall–Sundrum model

An attempt is made to present the contribution of the scalar unparticle on some scattering processes in the Randall–Sundrum (RS) model. We have evaluated the contribution of the scalar unparticle on the W-pair production cross-sections at International Linear Colliders (ILC). The results indicate that at the low values of the scaling dimension and the bounds on scale [Formula: see text] are around few TeV, the cross-sections are much enhanced, which is quite comparable with the W-production in the Standard Model and hence it is worthwhile to explore in future colliders.