Detecting the neutral top-pion at $e^{+}{e}^{-}$ colliders

Abstract

We investigate some processes of the associated production of a neutral top-pion ${\Pi }_t^0$ with a pair of fermions($e^{+}{e}^{-}\to f\bar{f}{\Pi }_t^0$) in the context of top-color-assisted technicolor(TC2) theory at future $e^{+}{e}^{-}$ colliders. The studies show that the largest cross sections of the processes $e^{+}{e}^{-}\to f^{\prime }\overline{f^{\prime }}{\Pi }_t^0(f^{\prime }=u,d,c,s,\mu ,\tau )$ could only reach the level of 0.01fb, we can hardly detect a neutral top-pion through these processes. For the processes $e^{+}{e}^{-}\to e^{+}{e}^{-}{\Pi }_t^0$, $e^{+}{e}^{-}\to t\bar{t}{\Pi }_t^0$ and $e^{+}{e}^{-}\to b\bar{b}{\Pi }_t^0$, the cross sections of these processes are at the level of a few fb for the favorable parameters and a few tens, even hundreds, of neutral top-pion events can be produced at future $e^{+}{e}^{-}$ colliders each year through these processes. With the clean background of the flavor-changing $t\bar{c}$ channel, the top-pion events can possibly be detected at the planned high luminosity $e^{+}{e}^{-}$ colliders. Therefore, such neutral top-pion production processes provide a useful way to detect a neutral top-pion and test the TC2 model directly.

Comments: 13 pages, 4 figures