Like Sign Top Pair Production via $e^+e^-\to h^0A^0 \to tt\bar c\bar c$
  We discuss the possibility and likelihood that one may observe {\it like sign} top quark pair production at the Linear Collider. In general two Higgs models, flavor changing couplings involving top quark could be quite sizable. Exotic neutral Higgs bosons may decay dominantly via $t\bar c$ or $\bar tc$ channels. At the linear collider, $e^+e^- \to h^0A^0$ or $H^0A^0$ production processes could lead to $b\bar bt\bar c$, $W^+W^-t\bar c$ or $tt\bar c\bar c$ (or $\bar t\bar tcc$) final states. These would mimic $T$-$\bar T$ mixing effect, except that $T$ mesons do not even form. 
George Wei-Shu Hou (National Taiwan University)