Heavy Quark Physics

这项建议请求支持锡拉丘兹大学小组的研究计划，该计划专注于b夸克和c夸克的弱衰变。尽管电弱相互作用的标准模型已经非常成功地解释了大多数现象，但该模型不能解释不同的夸克和轻子质量或夸克之间的不同耦合。该小组正在寻找模型数据中的偏差，以及在测量几个模型参数时的偏差。康奈尔电子储存环(CESR)正负电子对撞机上的CLEO实验一直处于b夸克和c夸克研究的前沿。例如，B0、B+和DS介子都是在CLEO上发现的。最近的CLEO III升级将探测器转变为更强大的仪器，采用了新的粒子识别探测器(RICH)、新的基于硅的顶点和跟踪设备以及新的快速电子设备，以适应CESR加速器增加的光度。RICH探测器是由这个小组设计、建造和委托的。费米实验室的质子-反质子Tevatron对撞机产生了大量的b夸克和c夸克，其速度比CESR高出1000-10000。然而，b夸克事件必须从比信号大1000倍的强子背景中提取出来，而在CESR，背景只比信号大4倍。BTeV实验旨在扩大电子-正电子实验的物理范围，其联合发言人是该小组的PI，最近获得了费米实验室管理层的第一阶段科学批准。

This proposal requests support for the research program of the Syracuse University group which is focused on the weak decays of the b-quark and the c-quark. Although the Standard Model of electroweak interactions has been very successful in explaining most phenomena, the model cannot explain the different quark and lepton masses or the different couplings between the quarks. This group is looking for deviations in the data from the model, and in measuring several model parameters. The CLEO experiment at the Cornell Electron Storage Ring (CESR) electron-positron collider has been at the forefront of studies of both the b- and c-quarks. For example, the B0, B+, and DS mesons were all discovered at CLEO. The recent CLEO III upgrade has transformed the detector into a more powerful instrument by incorporating a new particle identification detector (RICH), new silicon-based vertex and tracking devices, and new fast electronics to accommodate increased luminosity from the CESR accelerator. The RICH detector was designed, built, and commissioned by this group. The proton-antiproton Tevatron collider at Fermilab produces copious numbers of b- and c-quarks at rates 1000-10000 larger than at CESR. However, the b-quark events must be extracted from hadronic backgrounds that are a factor of 1000 larger than the signal, whereas at CESR the backgrounds are only a factor of four larger than the signals. The BTeV experiment, designed to extend the physics reach of the electron-positron experiments, and whose co-spokesman is the PI of this group, has recently received stage one scientific approval from Fermilab management.