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中微子质量起源、轻子味混合及其相关物理问题研究

Studying the Origin of Neutrino Masses, Lepton Flavor Mixings and Related Topics

【作者】 郑亚娟

【导师】 司宗国;

【作者基本信息】 山东大学 , 理论物理, 2012, 博士

【摘要】 中微子物理在粒子物理学、天文学和宇宙学研究领域都扮演着重要的角色。本文首先对中微子物理的研究现状进行了简要介绍,中微子震荡实验表明中微子味道之间有混合(PMNS矩阵),同时,我们注意到夸克的不同味道之间也存在混合(CKM矩阵),夸克味混合和轻子味混合之间可能存在一定的内在关联,如具有某种互补性,寻找中微子和夸克的味道混合之间的这种关联对于加深理解标准模型、探索超出标准模型的新物理具有重大意义;我们研究了夸克轻子互补性对于参数化形式的依赖及其随重整化群方程的演化。近来,中微子混合角的精确测量,促使人们对中微子混合类型进行新的探索,基于中微子混合角的最新实验结果,我们对以“双最大”和“三双最大”中微子混合类型为基的小角参数化展开方法进行重新检查,并提出了一种与当前实验相符的具有内部互补性的混合类型。中微子震荡表明中微子具有非兼并的静止质量。为了解释中微子的质量起源,有三种方法扩充标准模型,即引入重的Majorana中微子的第Ⅰ类跷跷板模型、引入重的标量三重态的第Ⅱ类跷跷板模型以及引入重的费米子三重态的第Ⅲ类跷跷板模型,在这些模型基础上,我们研究了当同时引进质量在几百GeV的Majorana中微子和标量Higgs三重态时,在LHC上研究了可能观测到的相应信号pp→l±l±+X,并分析了区分重的右手Majorana中微子和标量Higgs三重态的方法。

【Abstract】 Neutrinos play an essential role in particle physics, astronomy and cosmology. In this thesis, we first summarize the current theoretical and experimental status of neu-trino physics, and emphasize that neutrino oscillation has proved that neutrinos have non-degenerate masses and lepton flavors do mix. We know that there are also flavor mixings in quark sector. According to our experiences during the development of high energy physics, physics world is highly unified and symmetric. Hence, we believe that there might be some intrinsic correlation between quarks and leptons, e.g., quark lepton complementarity. Searching for the correlation between quarks and leptons is impor-tant in understanding the Standard Model and physics beyond the Standard Model. We discuss the parametrization dependence as well as the renormalization group running stability of quark lepton complementarity. Recently, the precise measurement of neu-trino flavor mixing parameters provoke the new exploration on neutrino mixing pattern. We rescrutinize the triminimal expansion based on bimaximal and tribimaximal mix-ing pattern. In addition, to understand the tiny mass of neutrino, seesaw mechanism is introduced. Seesaw mechanism includes type Ⅰ seesaw mechanism, which is real-ized by introducing heavy Majorana neutrinos, type Ⅱ seesaw mechanism, realized by introducing heavy scalar triplets and type Ⅲ seesaw mechanism, realized by intro-ducing fermion triplets. Further, we introduce Majorana particles and Scalar triplets at the same time and discuss the lepton-number-violating signatures induced by the heavy Majorana neutrinos which could be discovered at the CERN Large Hadron Collider.

  • 【网络出版投稿人】 山东大学
  • 【网络出版年期】2012年 12期
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