Testing Technicolor Models via Top Quark Pair Production in High Energy   Photon Collisions
  Pseudo-Goldstone boson contributions to $t\bar{t}$ production rates in technicolor models with and without topcolor at the $\sqrt{s}=0.5 and 1.5$ TeV photon colliders and hadron colliders are reviewed. For reasonable ranges of the parameters, the contributions are large enough to be experimentally observable. Models with topcolor, without topcolor and the MSSM with $\tan\beta\geq 1$ can be experimentally distinguished. 
Hong-Yi Zhou, Yu-Ping Kuang, Chong-Xing Yue, Hua Wang, Gong-Ru Lu