在额外一维量子电动力学的背景下,对光子自能、费米子自能和费米子顶点函数在一个回路上进行了全面的分析。在以无限多个卡鲁扎-克莱因场为特征的5维理论中,单圈振幅既包括离散的和,也包括连续的和,$\sum^\infty_{n=1}\int d^4k$,它可以发散。使用维正则化,我们表示这样的总和作为产品的伽玛和爱泼斯坦功能,都定义在复杂的平面上,与发散所产生的极点,这些功能的极限为$ D \to 4$。利用Epstein函数的分析性质,我们证明了由Kaluza-Klein和产生的紫外发散可以一致地重整化,这意味着相应的重整化量在非常大的紧化尺度$R^{-1}$的极限下约化为通常的QED量.在单圈水平上研究了QED的主要特征。我们使用质量相关的$μ$ -计划计算,在QED与任意数量的额外维度$n$,满足所有期望的物理要求的beta函数。我们认为,在这种类型的理论,与一个大的质量谱覆盖了很宽的能量范围内,β函数不应该使用质量无关的重整化方案计算。我们证明了对任何能量$μ$,β函数都是有限的.特别是,它减少到通常的QED结果$e^3/12π^2$为$m\ll μ\ll R^{-1}$和消失的$m\gg μ$,与$m$通常的费米子质量。在整个工作中,去耦性质的Epstein函数的分析性质得到的所有结果的强调。
英文摘要:
A comprehensive analysis on the photon self-energy, the fermion self-energy, and the fermion vertex function is presented at one loop in the context of quantum electrodynamics (QED) with 1 extra dimension. In 5-dimensional theories, characterized by an infinite number of Kaluza-Klein fields, one-loop amplitudes involve discrete as well as continuous sums, $\sum^\infty_{n=1}\int d^4k$, that could diverge. Using dimensional regularization, we express such sums as products of gamma and Epstein functions, both defined on the complex plane, with divergences arising from poles of these functions in the limit as $ D \to 4$. Using the analytical properties of the Epstein function, we show that the ultraviolet divergences generated by the Kaluza-Klein sums can be consistently renormalized, which means that the corresponding renormalized quantities reduce to the usual ones of QED at the limit of a very large compactification scale $R^{-1}$. The main features of QED at the one-loop level were studied. We use the mass-dependent $μ$-scheme to calculate, in QED with an arbitrary number $n$ of extra dimensions, a beta function fulfilling all desirable physical requirements. We argue that in this type of theories, with a large mass spectrum covering a wide energy range, beta functions should not be calculated by using mass-independent renormalization schemes. We show that the beta function is finite for any energy $μ$. In particular, it reduces to the usual QED result $e^3/12π^2$ for $m\ll μ\ll R^{-1}$ and vanishes for $m\gg μ$, with $m$ the usual fermion mass. Throughout the work, the decoupling nature of all our results obtained from the analytical properties of the Epstein function is stressed.
Extracting Majorana Properties in the Throat of Neutrinoless Double Beta Decay
假设中微子是马约拉纳粒子,我们探索什么信息可以推断出未来的强限制(即非观测)的无中微子双β衰变。具体来说,我们考虑的情况下,质量层次是正常的和不同的贡献,有效质量$\langle m \rangle_{ee}$部分取消。我们讨论了如何固定两个马约拉纳CP阶段同时从马约拉纳三角形和它如何限制最轻的中微子质量$m_1$在一个狭窄的窗口。在这种情况下,对于较大的$\langle m \rangle_{ee}$,两个马约拉纳CP相位甚至比通常情况下更好地确定。我们表明,在这些预测的不确定性可以显着减少反应堆中微子实验的补充测量,特别是中等基线版本JUNO/RENO-50。我们还估计了在$\langle m \rangle_{ee}$上推断非平凡Majorana CP相位所需的精度,并且上限$\langle m \rangle_{ee} \lesssim 1\,\mbox{meV}$为未来无中微子双β衰变实验的设计设定了一个目标。
Gauge and Infrared Properties of Hadronic Structure of Nucleon in Neutron Beta Decay to Order O(α/π) in Standard V - A Effective Theory with QED and Linear Sigma Model of Strong Low--Energy Interactions
Infrared Properties of Hadronic Structure of Nucleon in Neutron Beta Decays to Order O(α/π) in Standard V - A Effective Theory with QED and Linear Sigma Model of Strong Low--Energy Interactions
Gauge Properties of Hadronic Structure of Nucleon in Neutron Radiative Beta Decay to Order O(alpha/pi) in Standard V - A Effective Theory with QED and Linear Sigma Model of Strong Low--Energy Interactions
在弱相互作用的标准V-A理论、量子电动力学(QED)和低能强强子相互作用的线性σ模型(LsM)下,分析了中子辐射β衰变中中子和质子强子结构的规范性质。我们表明,费曼图,描述强低能相互作用在LsM的树近似的中子辐射β衰变的振幅的强子结构的贡献,规范不变。反过来,在单强子环近似下描述强子-光子相互作用贡献的完整费曼图也不是规范不变的。在标量σ介子的无限极限中,再现当前的代数结果(Weinberg,Phys. Rev. Lett. 18,188(1967)),而对于大核子质量膨胀的主导阶,费曼图违反规范不变性,对中子辐射β衰变的振幅没有贡献,这与Sirlin对中子β衰变中强低能相互作用的分析一致。我们断言,中子和质子强子结构的规范非不变费曼图的出现问题与以下有关。有效V-A弱相互作用的顶点不属于包含LsM和QED的组合量子场论。我们认为,在标准电弱模型(SEM)和LsM的组合量子场论中,当弱相互作用的有效V-A顶点是W^- -电弱玻色子交换的结果时,可以得到中子β衰变中强子与实光子和虚光子耦合的Feynman图的规范不变集.
Radiative tritium beta-decay and the neutrino mass
3 H β衰变中电子能谱的形状允许直接测定中微子质量的绝对标度;对电子能谱的高度精确的理论描述是经验任务所必需的。我们更新了Sirlin对核β衰变的外辐射修正的计算,以考虑电子探测器的非零能量分辨率。在以前的~ 3 H β衰变研究中,外辐射修正都被忽略了,只包括了库仑修正。这种忽略人为地以一种潜在的重要方式推动m_nu^2 < 0。我们提出了一个计算的理论光谱适当的提取中微子质量的亚电子伏特制度。