Constraining variations in the fine-structure constant, quark masses and the strong interaction
Constraining variations in the fine-structure constant, quark masses and the strong interaction
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DOI：
10.1007/978-3-540-40991-5_9
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发表时间：
2003-10
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影响因子：
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通讯作者：
Michael T. Murphy;V. Flambaum;J. Webb;Vladimir V. Dzuba;J. Prochaska;A. Wolfe
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文献类型：
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作者：
Michael T. Murphy;V. Flambaum;J. Webb;Vladimir V. Dzuba;J. Prochaska;A. Wolfe
摘要：我们通过 143 个类星体吸收系统的 Keck/HIRES 光谱在红移范围 0.2 <zabs< 4.2 范围内提供精细结构常数变化的证据。这包括 15 个新系统，大部分处于高 z(zabs> 1.8)。我们最稳健的估计是加权平均值Δα/α= (–0.57 ▒ 0.11) Î 10–5。我们回应最近对用于提取这些约束的多多重方法的批评。低 z 值下最重要的潜在系统误差是吸收云和实验室中 Mg 重同位素丰度差异很大的可能性：吸收体中 25,26 Mg 的丰度较高可以解释低 z 结果。需要大约等量的 24Mg 和 25,26Mg 混合物。对银河系恒星的观测通常显示出较低的 25,26Mg 同位素分数，代表吸收体的低金属丰度。通过增加高红移的中等质量恒星数量可以实现更高的值，这与观测到的吸收系统元素丰度不一致。目前，所有观测证据都与变化的α结果一致。寻找基本常数变化的另一种有前景的方法是比较不同的原子钟。在这里，我们计算了核磁矩对夸克质量的依赖性，并从最近的原子钟实验中获得了 α 变化的极限，其中包括 H、Rb、Cs、Hg+ 的超精细跃迁和 Hg+ 的光学跃迁。
AbstractWe present evidence for variations in the fine-structure constant from Keck/HIRES spectra of 143 quasar absorption systems over the redshift range 0.2 <zabs< 4.2. This includes 15 new systems, mostly at high-z(zabs> 1.8). Our most robust estimate is a weighted meanΔα/α= (–0.57 ▒ 0.11) Î 10–5. We respond to recent criticisms of the many-multiplet method used to extract these constraints. The most important potential systematic error at low-zis the possibility of very different Mg heavy isotope abundances in the absorption clouds and laboratory:higherabundances of25,26Mg in the absorbers may explain the low-zresults. Approximately equal mixes of24Mg and25,26Mg are required. Observations of Galactic stars generally showlower25,26Mg isotope fractions at the low metallicities typifying the absorbers. Higher values can be achieved with an enhanced population of intermediate mass stars at high redshift, a possibility at odds with observed absorption system element abundances. At present, all observational evidence is consistent with the varying-αresults.Another promising method to search for variation of fundamental constants involves comparing different atomic clocks. Here we calculate the dependence of nuclear magnetic moments on quark masses and obtain limits on the variation ofαandfrom recent atomic clock experiments with hyperfine transitions in H, Rb, Cs, Hg+and an optical transition in Hg+.