在γγ对撞机上通过味改变过程探测中性toppion介子

Probing the neutral toppion via a flavor-changing process at the γγ colliders

在Topcolor辅助的Technicolor(TC2)模型下,研究了γγ对撞中产生中性toppion介子(Π0t)的味改变过程:γγ→t cΠ0t.计算结果表明,在未来直线对撞机上(如TESLA),质心能量s对产生截面的影响很大.当s=1600GeV时,在多数参数区间内t cΠ0t的产生截面约为1fb.而当Π0t的质量MΠ较小时,由于共振效应,t cΠ0t产生截面可达几十个fb.由于t cΠ0t的产生过程背景比较干净,研究表明,在TESLA对撞机上应该可以探测到Π0t的产生事例.此外,实验上还应该能探测到toppion charm不变质量分布中的共振峰.因此,γγ→t cΠ0t是探测中性toppion介子(Π0t)的一个理想过程,可为实验上检验TC2模型提供直接的证据.

In the framework of topcolor-assisted technicolor(TC2) model, we study a flavor-changing process γγ→ tΠ~0_t at the γγ colliders.It is much easier to realize γγ collision in the linear collides, such as TESLA.The results show that the center mass energy s effects the cross section strongly.When s=1 600 GeV, the production cross section of tΠ~0_t is about 1 fb in most parameter regions of TC2 model. Furthermore,The resonance effect can enhance the cross section to a few tens of fb when toppion mass is small.Because of the clear background, the toppion events can possibly be detected at TESLA . In addition,there are a narrow peak in the toppion-charm invariant mass distribution which can be detected.Therefore, the flavor-changing process γγ→ tΠ~0_tis a ideal channal to detect the neutral toppion which can provide direct proof to test the TC2 model.