在ATLAS实验中寻找伴随单top夸克产生的带电Higgs粒子

项目名称： 在ATLAS实验中寻找伴随单top夸克产生的带电Higgs粒子

项目编号： No.11475106

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 冯存峰

作者单位： 山东大学

项目金额： 96万元

中文摘要： 寻找超出标准模型的新物理是粒子物理的热点问题，而带电Higgs粒子的发现将会成为新物理存在的确凿证据，质量小于top夸克的轻带电higgs粒子存在空间已被压缩，寻找质量大于top夸克的重带电Higgs粒子变的愈发重要。2015年，LHC将在14TeV对撞能量下运行，有望打开新物理的窗口。本课题将研究利用ATLAS实验未来14TeV能量下的数据，通过伴随单top夸克产生过程，在含有轻子的末态中，寻找重带电Higgs粒子。课题内容将研究利用多参量分析likelihood方法优化带电Higgs粒子质量重建，并利用多参量分析BDT方法分辨信号事例，在180-1000GeV质量空间内，扫描带电Higgs粒子存在的显著性，期望发现带电Higgs粒子。为降低事例堆积对丢失横动量的重建精度的影响，本课题还拟开展利用径迹探测器重建丢失横动量的研究。

中文关键词： 大型强子对撞机；数据分析；标准模型

英文摘要： Search for the new physics beyond Standard Model is one hot topic in particle physics, and the observation of a charged Higgs boson would clearly indicate new physics beyond the Standard Model. The light charged Higgs, mass less than top quark, has been constrained in limit mass space. So, it's more important to search the heavy charged Higgs, heavier than top quark mass. LHC will run under 14TeV collision energy in 2015, and one window for new physics will be open probably under this new energy frontier. In this study, heavy charged Higgs will be searched through tb channel based on collision data at 14TeV collected by ATLAS detector. This study covers the charged Higgs production and decay processes where one top quark decays leptonically and the other decays hadronically. In this study, the combinatoric background invloved when reconstructing the charged Higgs is a challenging problem, but can be overcome by employing one multivariate techniques. A boost decision tree method will be used to discriminate the signal events. The significance of charged Higgs will be derived for the mass range 180GeV-1000GeV. By the way, the reconstruction method for miss energy based on track detectors will be study in order to improve the prisicion of miss energy which was deviated by high pileup in ATLAS RunII.

英文关键词： Large hardron collider;data analysis;standard model