Effect of top quark spin on the unparticle couplings in $\gamma\gamma \to t\bar{t}$

Abstract

We investigate the potential of γ γ collisions to probe scalar unparticle couplings via top–antitop quark pair production. We find 95% confidence level limits on the unparticle couplings with an integrated luminosity of 500 fb−1 and an energy of \(\sqrt{s}=1\) TeV. We investigate the effect of the top quark spin polarization on the unparticle couplings. It is shown that spin polarization of the top quark leads to a significant improvement in the sensitivity limits.