AMS02电磁量能器三维重建

研究了AMS02电磁量能器簇射三维重建, 发展出一个新的三维重建程序, 并用 蒙特卡罗模拟以及2002年束流测试数据对其进行了检验．该程序应用两次方向 重建、结合光纤衰减修正、横向以及纵向能量泄漏补偿, 完整地对事例进行了 重建, 得到了较为理想的能量分辨率和角度分辨率．     

46.8MeV的(-p)+12C非弹性散射

在Glauber多重散射理论框架下,使用跃迁密度方法和三种NN湮没势,计算了46.8MeV的反质子在12C上的非弹性散射微分截面.理论曲线与实验数据符合得较好.     

Physical Realization of Quantum C-Not Gate

We investigate a Heisenberg spin cluster with two particles controlled by a time-dependent magnetic field. The system is controlled by tuning the amplitude, frequency, and interaction time of the three-step time-dependent magnetic field. Then we solve the time-dependent Schrodinger equation of the two-particle system, and obtain the time evolution operator. By the three-timestep interaction, the wavefunction evolves from the initial state to the final state, and the total evolution operator can be expressed as a product of the three evolution operators. By adjusting the physical parameters, the key two-qubit logic gate, the C-Not gate, can be realized physically.     

Discrimination of converted photons and neutral pions at high energies

In the LHC experiment, the H→γγ channel provides a clean nal state with an effective mass peak that is reconstructed with great precision, despite the small branching ratio. As a consequence, the H→γγ channel is one of the most promising channels for the Higgs discovery in the very low mass region. In order to increase the sensitivity of the Higgs search, background rejection rate is very important, so γ/π⁰ discrimination is one of the key points in the analysis. At least 40% of photons will convert with the experience of ATLAS and CMS. We constructed electromagnetic calorimeter (ECAL) in GEANT4 simulation, using 6 variables which have different shapes between converted γ and π⁰, with the TMVA (Toolkit for Multivariate Data Analysis) to do the separation. With this method we can get 30% to 60% π⁰ rejection efficiency when keeping 90% converted γ efficiency, in the region of transverse momentum 15 GeV to 75 GeV, not only in MC sumulation but also in real data.     

A study of hadronic shower development in the ECAL of the alpha magnetic spectrometer Ⅱ

In this paper, we studied the development of hadronic shower in an electromagnetic calorimeter of Alpha Magnetic Spectrometer Ⅱ. Two parametrized empirical formulae were proposed to describe the hadronic shower shape in calorimeter. Using 100 GeV proton beam incident on the center of the ECAL, detailed plots of lateral and longitudinal hadronic shower behavior were given and we found the formulae can describe the development of the hadronic shower with the test beam data. The possible application of the parametrized formulae including e^±-π^± discrimination and tau jet reconstruction was discussed.     

温度和场冷间隙对高温超导磁悬浮系统弛豫的影响

悬浮力是高温超导磁悬浮列车运行中的一个至关重要的参数.悬浮力的弛豫特性是高温超导磁悬浮列车安全运行的一大阻碍.适度降低工作温度是有效改善悬浮力弛豫特性的有效手段之一.本文从数值计算和实验两个层面研究了不同冷却温度和不同场冷间隙下的悬浮力的弛豫现象.发现悬浮力的弛豫现象随着超导块冷却温度的降低而减弱，随着场冷间隙的增大而略微增大，但是随着冷却温度的降低，增大程度会有所减弱.该研究有助于通过合理设计高温超导材料工作温度，以提高磁悬浮系统性能表现.