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电弱盒对超额允许的核和中子β衰变的贡献的格子QCD计算
Peng-Xiang Ma1, Xu Feng1,2,3, Mikhail Gorchtein4,5
1School of Physics, Peking University, Beijing 100871, China.
Physical review letters
|May 28, 2024
概括
我们使用格子QCD计算了轴性马W盒贡献,这是β衰变理论中的关键因素. 这提高了对V的确定性,减少了CKM统一性的紧张.
科学领域:
- 核物理 核物理 核物理
- 量子色态动力学 量子色态动力学
- 粒子物理学 粒子物理学
背景情况:
- 轴性马W-box贡献对于精确的V_{ud}的确定从超允许的衰变至关重要.
- 这一贡献中的理论不确定性会影响CKM统一性测试.
- 之前的计算对于这个特定的术语缺乏格子QCD精度.
研究的目的:
- 执行第一个晶格 QCD 计算轴性玛 W-box 贡献 (□_{γW}^{VA}).
- 为了减少理论上的不确定性,V_{ud}的取.
- 调查与卡比博 - 科巴亚希 - 马斯卡瓦 (CKM) 统一主义的紧张关系的影响.
主要方法:
- 在物理的 pion 质量上利用了两个域壁的 fermion 合集.
- 在核子四点相关函数中采用随机散射场技术.
- 通过无限体积重建和连续超算,纳入了远距离贡献.
主要成果:
- 计算出来的 □_{γW}^{VA} = 3.65(7)_{lat}(1)_{PT} × 10^{-3}.
- 确定了V_{ud}的数量 = 0.97386 11_{exp} 9_{RC} 27_{NS}.
- 从2.1σ降低了CKM统一性的紧张关系,从1.8σ降低到1.8σ.
结论:
- 格子QCD计算为 □_{γW}^{VA}.提供了一个精确的值.
- 改进的 "V_{ud}" 值稍微缓解了与 CKM 统一性的差异.
- 需要进一步计算诸如 □_{γW}^{VV} 这样的相关项.
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