Department of Physics, University of Tokyo, Tokyo 113-0033, Japan.
Phys Rev Lett. 2009 Oct 2;103(14):141803. doi: 10.1103/PhysRevLett.103.141803.
Long-lived charged massive particles (CHAMPs) appear in various particle physics models beyond the standard model. In this Letter, we discuss the prospects for studying the stopping and decaying events of such long-lived CHAMPs at the LHC detectors, and show that the lifetime measurement (and the study of decay products) is possible with the LHC detectors for a wide range of the lifetime O(0.1)-O(10(10)) sec, by using periods of no pp collision. Even a short lifetime of order 1 sec can be measured by (i) identifying the stopping event with the on-line event filter, (ii) immediately making a beam-dump signal which stops the pp collision of the LHC, and at the same time (iii) changing the trigger menu to optimize it for the detection of a CHAMP decay in the calorimeter. Other possibilities are also discussed.
长寿命带电重粒子（CHAMPs）出现在超越标准模型的各种粒子物理模型中。在这封信中，我们讨论了在 LHC 探测器上研究这些长寿命 CHAMPs 的停止和衰变事件的前景，并表明通过使用无 pp 碰撞的时间段，LHC 探测器可以在广泛的寿命 O(0.1)-O(10^{10}) 秒范围内进行寿命测量（和衰变产物研究）。即使寿命只有 1 秒左右，也可以通过以下方法来测量：（i）使用在线事件筛选器识别停止事件，（ii）立即发出束流dump 信号，停止 LHC 的 pp 碰撞，同时（iii）改变触发菜单，使其最优化以在量热器中检测 CHAMP 衰变。其他可能性也进行了讨论。
