Study of the single neutral top pion production process atγγcollider

Abstract

$\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\Pi}}_{t}^{0}$ is the major production mechanism of the neutral top pion at the linear colliders. In this paper, we calculate the cross section of the process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\Pi}}_{t}^{0}$ and discuss the potential to observe the neutral top pion via its various decay modes at the planned International Linear Collider. The study shows that, among the various neutral top-pion production processes at the linear colliders, the cross section of $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\Pi}}_{t}^{0}$ is the largest one which can reach the level of ${10}^{1}\ensuremath{-}{10}^{2}\text{ }\text{ }\mathrm{fb}$. Because of the existence of the tree-level flavor-changing coupling ${\ensuremath{\Pi}}_{t}^{0}t\overline{c}$, $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\Pi}}_{t}^{0}\ensuremath{\rightarrow}t\overline{c}$ can provide enough number of typical signals to identify the neutral top pion with the clean SM background. Therefore, the process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\Pi}}_{t}^{0}$ plays an important role in searching for the neutral top pion and tests the TC2 model.