Neutral top-pion and $t\gamma (z)$ production at the HERA and THERA colliders

Chongxing Yue, Dongqi Yu, Zhengjun Zong

In the context of top-color assisted technicolor ($TC2$) models, we calculate the contributions of the neutral top-pion ${\pi }_t^0$ to $t\gamma$ and $tz$ production via the processes $…