【作者】 吴伟；

【导师】 罗民兴； 朱国怀；

【作者基本信息】 浙江大学 ， 理论物理， 2009， 博士

【摘要】 本文系统分析了对撞机物理的基本技术,并给出了LHC上模拟硬散射过程的基本程序实现办法,包括PDF的读取、动力学部分的生成、运动学处理、蒙特卡罗积分和运动学分布等。应用这些技术分析了Higgsless类模型预言的高质量矢量KK激发态Z1在LHC上的信号。Z1衰变主要是两个衰变道Z1→W+W-和Z1→tt,据此我们选取两个特定的观测道：pp→jj+e±+e±+ET和pp→jjjj+e±+e±+ET。我们得到的结果是,LHC观测Higgless类模型中的Z1,在100fb-1的积分亮度和5σ的置信度下,假设100%的衰变宽度,使用第一个道,其探测的质量极限可以到达650 GeV,使用第二个道,可以到达560 GeV。在Z1质量为500 GeV时,在100fb-1的积分亮度和5σ的置信度下,探测Z1→W+W-的衰变分支比可以到达25%,探测Z1→tt的衰变分支比可以到达60%。本文还分析了非粒子物理在Z峰上的唯象行为,以试图用其解释LEP上b夸克的前后不对称性的测量值与标准模型拟合值的背离问题。我们认为在其它物理可观测量的限制下,大部分的参数空间都被排除。只有在非粒子项与标准模型粒子耦合是矢量型主导,并且其与b夸克耦合远大于其与其他夸克耦合时,才有一定的参数空间以解决A(?)的反常问题。更多还原

【Abstract】 Techniques of collider physics are systematically reviewed in this thesis and hard pro-cess simulation at the LHC is analyzed in detail. As an application, we study the LHC signatures of new neutral gauge boson Z1 which is predicted by Higgsless models. Z1 can decay to W pair or tt, which provide two different channels to observe Z1. We investigated both two channels and choose two specific interaction chain pp→jj+e±+e±+ET and PP→jjjj+e±+e±+ET for each channel. Both channels are promising to discover Hig-gsless Z1 at the LHC. In both cases, we propose to focus on the multijet+e±e±+ET final states. We find that it is possible to observe the Z1 resonance upto 650 GeV at a 5σlevel with an integrated luminosity of 100 fb-1 for a dominant WW channel, and 560 GeV for a dominant of tt channel. The unparticle phenomenology on the Z pole is also studied in this thesis, with the hope to solve the 3a anomaly of A(?) by unparticle sector. Unfortunately, for most part of the parameter space except certain particular regions, the anomaly could not be explained away plausibly, when constraints from other LEP observables are taken into account.更多还原