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arXiv 1104.3700nucl-th
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双β衰变、原子核结构与超标准模型物理

Double Beta Decay, Nuclear Structure and Physics beyond the Standard Model

Amand Faessler

摘要:

无中微子双β衰变($0νββ$)是目前已知的唯一一个在狄拉克中微子(不同于其反粒子)和马约拉纳中微子(与其反粒子相同)之间进行分离的实验。此外,$0νββ$还能确定中微子质量的绝对尺度。这在中微子振荡中是不可能的。为了确定中微子的质量,必须假定轻的Majorana中微子交换是$0νββ$的主要机制,并且这种跃迁的矩阵元可以可靠地计算。在这种机制中,实验$0νββ$跃迁振幅是轻左手有效Majorana中微子质量和跃迁矩阵元的乘积。综述了近年来文献中采用的准粒子无规相近似(QRPA)、壳模型(SM)、投影Hartree-Fock-Bogoliubov(PHFB)和相互作用玻色子模型(IBM 2)等方法以及这些方法中矩阵元的可靠性。第二部分研究了如何从不同核的$0νββ$衰变数据中确定主导机制。给出了转换矩阵元的显式表达式。示出了允许测试CP(电荷和宇称共轭)违反可能的干扰项。

英文摘要:

Neutrinoless Double Beta Decay ($0νββ$) is presently the only known experiment to distinguisch between Dirac neutrinos, different from their antiparticles, and Majorana neutrinos, identical with their antiparticles. In addition $0νββ$ allows to determine the absolute scale of the neutrino masses. This is not possible with neutrino oscillations. To determine the neutrino masses one must assume, that the light Majorana neutrino exchange is the leading mechanism for $0νββ$ and that the matrix element of this transition can ba calculated reliably. The experimental $0νββ$ transition amplitude in this mechanism is a product of the light left handed effective Majorana neutrino mass and of this transition matrix element. The different methods, Quasi-particle Random Phase Approximation (QRPA), Shell Model (SM), Projected Hartree-Fock-Bogoliubov (PHFB) and Interacting Boson Model (IBM2) used in the literature and the reliability of the matrix elements in these approaches are reviewed. In the second part it is investigated how one can determine the leading mechanism or mechanisms from the data of the $0νββ$ decay in different nuclei. Explicite expressions are given for the transition matrix elements. is shown, that possible interference terms allow to test CP (Charge and Parity conjugation) violation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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