宇宙线探测系统的建立及阻抗板探测器的测试

在实验室内建立了一套宇宙线测试系统(CORTS)，并对一个大面积CMS RE1/2 RPC的完整样品进行了系统的测试. 结果为RPC的探测效率约85%，时间分辨率为0.87±0.08ns，空间分辨本领为1.5根读出条宽度，与CERN束流测试中得到的数据基本吻合. 对比表明采用宇宙线测试可以可靠地获得若干关键的RPC探测器性能指标.     

LHC上μ子探测器阻抗板气体室

对一个完全由中国材料制作的阻抗板气体室探测器和一个由意大利提供的阻抗板气体室组装的探测器的束流测试结果进行了细致地分析和比较. 束流测试是在CERN的GIF进行的. 测试过程中用一个很强的¹³⁷Cs源来近似模拟未来LHC上μ子探测器的本底环境. 分析结果表明，两个样品都具有良好的时间和空间分辨率，能满足未来LHC上CMS实验的要求.在高γ 辐射本底下两个样品的探测效率不同，给出了理论分析.     

北京谱仪顶点探测器触发效率的研究

模拟了北京谱仪(BESⅡ)顶点探测器的触发判选系统,发现对于某些带次级顶点的衰变道,其顶点探测器触发效率较低.并由此对BESⅡ中与效率相关的物理过程作了讨论,给相应的触发设计者提供参考.     

Fast computation of observed cross section for ψ'→PP decays

It has been conjectured that the relative phase between strong and electromagnetic amplitudes is universally -90° in charmonium decays. ψ' decaying into a pseudoscalar pair provides a possibility to test this conjecture. However, the experimentally observed cross section for such a process is depicted by the two-fold integral, which takes into account the initial state radiative (ISR) correction and energy spread effect. Using the generalized linear regression approach, a complex energy-dependent factor is approximated by a linear function of energy. Taking advantage of this simplification, the integration of ISR correction can be performed and an analytical expression with accuracy at the level of 1% is obtained. Then, the original two-fold integral is simplified into a one-fold integral, which reduces the total computing time by two orders of magnitude. Such a simplified expression for the observed cross section usually plays an indispensable role in the optimization of scan data taking, the determination of systematic uncertainty, and the analysis of data correlation.