从格子QCD计算 ηc→2γ衰变宽度的第一原理计算
Yu Meng1, Xu Feng2, Chuan Liu3
1School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China.
Science bulletin
|August 7, 2023
概括
我们使用格子QCD计算了eta_c到2光子衰变宽度. 我们的结果显示了与当前的实验值存在显著的紧张关系,这表明需要进一步调查.
科学领域:
- 量子色态动力学 (QCD) 是一个
- 粒子物理学 粒子物理学
- 子光谱学 子光谱学
背景情况:
- 对于两个光子 (2γ) 的 eta_c (ηc) 的衰变宽度是测试子结构理论模型的关键可观测值.
- 以前的计算和实验测量显示了一些差异,需要进一步的理论审查.
研究的目的:
- 为了执行精确的格子QCD计算 ηc→2γ衰变宽度.
- 采用独立于模型的方法来最大限度地减少理论不确定性.
- 调查和解决与现有实验数据的紧张关系.
主要方法:
- 使用了网格QCD与Nf=2扭曲质量费米离子组合.
- 采用了一种新的方法,避免对外形状因子的动量推断.
- 通过多州匹配计算并删除激发状态贡献.
- 通过使用三个格子间距进行连续推断.
主要成果:
- 获得了 [公式] keV 的衰变宽度.
- 与粒子数据组的[FORMULA] keV值相比,发现了一个显著的差异 (2.9σ张力).
- 证明了有限体积效应和魔力夸克质量调得到了良好的控制.
结论:
- 计算的 ηc→2γ 衰变宽度与实验平均值有显著的偏差.
- 这一结果突出了当前实验数据或理论假设的潜在问题.
- 需要进一步的理论和实验研究来澄清这种差异.
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