Tritium β-decay in chiral effective field theory
Tritium β-decay in chiral effective field theory
复制标题
手性有效场理论中的氚β衰变
DOI：
10.1103/physrevc.94.024003
复制
发表时间：
2016
影响因子：
3.1
通讯作者：
M. Viviani
中科院分区：
文献类型：
--
作者：
A. Baroni;L. Girlanda;A. Kievsky;L. Marcucci;R. Schiavilla;M. Viviani
我们通过在改变电荷的弱电流中包含最近在核手性有效场理论（$$\chi$$ EFT）中导出的一个环的修正，来评估氚$$\beta$$衰变中的费米和伽莫夫-泰勒（GT）矩阵元素。三核子波函数由薛定谔方程的超球谐波解得到，具有对应于$$\chi$$ EFT （N3LO/N2LO组合）或介子交换现象学（AV18/UIX组合）的二核子和三核子势。我们发现，相对而言，轴向电流中环路修正的贡献与单介子交换的贡献一样大（在某些情况下，占主导地位），后者名义上发生在功率计数的较低阶。此外，我们还提供了在N3LO/N2LO和AV18/UIX计算中再现实验GT矩阵元素和三核子结合能所需的低能常数乘以接触轴流和三核子势的值。
We evaluate the Fermi and Gamow-Teller (GT) matrix elements in tritium $$\beta$$-decay by including in the charge-changing weak current the corrections up to one loop recently derived in nuclear chiral effective field theory ($$\chi$$ EFT). The trinucleon wave functions are obtained from hyperspherical-harmonics solutions of the Schroedinger equation with two- and three-nucleon potentials corresponding to either $$\chi$$ EFT (the N3LO/N2LO combination) or meson-exchange phenomenology (the AV18/UIX combination). We find that contributions due to loop corrections in the axial current are, in relative terms, as large as (and in some cases, dominate) those from one-pion exchange, which nominally occur at lower order in the power counting. Furthermore, we also provide values for the low-energy constants multiplying the contact axial current and three-nucleon potential, required to reproduce the experimental GT matrix element and trinucleon binding energies in the N3LO/N2LO and AV18/UIX calculations.