Super flat IR beam pipe for B factory and Linear collider

研究了超平互作用区束管的设计参数。根据前几年所做的研究，我们将束管的内部尺寸设置为1 mm高，10 mm宽，16 mm长。然后，我们研究了束管的材料和厚度，并决定使用500微米厚的铍作为真空壁。然后，我们使用的设计参数模拟的物理过程的B工厂使用GEANT 4探测器模拟工具在欧洲核子研究中心开发。今年，我们研究了从电子正电子碰撞产生的连续夸克-反夸克对中分离出B介子和反B介子。对于其中B介子衰变成K介子和π介子的衰变模式，当使用超平束管时，衰变顶点的分辨率从约49微米提高到15微米，而标签侧顶点的分辨率从约103微米提高到24微米，从而导致顶点分离从130微米提高到38微米。根据衰减模式的不同，这将信噪比提高约13 - 60

We studied design parameters for the super flat interaction region beam pipe. Following the study done previous years, we set the inner dimension of the beam pipe to be 1mm high, 10mm wide and 16 mm long. We then studied the material and thickness of the beam pipe and se decided to use 500 micron thick Beryllium as the vacuum wall. We then used the design parameter to simulate the physics processes for the B factory using GEANT4 detector simulation tool developed at CERN. This year, we studied to separate B and anti B meson production from continuum quark-anti quark pair production from the electron positron collision. For decay mode where B meson decaying into K meson and pi meson the resolution of the decay vertex improves from about 49 micron to 15 micron when using the super flat beam pipe while the resolution of the tag side vertex improves from about 103 microns to 24 micron, thus resulting the improvement in vertex separation from 130 microns to 38 microns. This improves the signal to noise ration about 13〜60% depending on the decay modes