标题： 对 Yb$^+$原子钟和 Cs 原子钟的比较得出的$m_p/m_e$时间变化的改进限制 显示英文标题

标题： Improved limit on a temporal variation of $m_p/m_e$ from comparisons of Yb$^+$ and Cs atomic clocks

摘要： 对原子能级之间不同跃迁频率的精确测量，随时间变化用于研究精细结构常数$\alpha$和质子与电子质量比$\mu$的时间变化。我们测量了$^2S_{1/2}\rightarrow {^2F_{7/2}}$电三极（E3）跃迁的频率，在$^{171}$Yb$^+$中相对于两个铯原子喷泉钟为$f(E3) = 642\,121\,496\,772\,645.36(25)$~Hz，改进后的分数不确定度为$3.9\times 10^{-16}$。 此跃迁频率对$\alpha$的变化表现出强烈的敏感性。 Together with a number of previous and recent measurements of the $^2S_{1/2}\rightarrow {^2D_{3/2}}$ electric quadrupole transition in $^{171}$Yb$^+$ and with data from other elements, a least-squares analysis yields $(1/\alpha)(d\alpha/dt)=-0.20(20)\times 10^{-16}/\mathrm{yr}$ and $(1/\mu)(d\mu/dt)=-0.5(1.6)\times 10^{-16}/\mathrm{yr}$, confirming a previous limit on $d\alpha/dt$ and providing the most stringent limit on $d \mu/dt$ from laboratory experiments. 显示英文摘要

摘要： Accurate measurements of different transition frequencies between atomic levels of the electronic and hyperfine structure over time are used to investigate temporal variations of the fine structure constant $\alpha$ and the proton-to-electron mass ratio $\mu$. We measure the frequency of the $^2S_{1/2}\rightarrow {^2F_{7/2}}$ electric octupole (E3) transition in $^{171}$Yb$^+$ against two caesium fountain clocks as $f(E3) = 642\,121\,496\,772\,645.36(25)$~Hz with an improved fractional uncertainty of $3.9\times 10^{-16}$. This transition frequency shows a strong sensitivity to changes of $\alpha$. Together with a number of previous and recent measurements of the $^2S_{1/2}\rightarrow {^2D_{3/2}}$ electric quadrupole transition in $^{171}$Yb$^+$ and with data from other elements, a least-squares analysis yields $(1/\alpha)(d\alpha/dt)=-0.20(20)\times 10^{-16}/\mathrm{yr}$ and $(1/\mu)(d\mu/dt)=-0.5(1.6)\times 10^{-16}/\mathrm{yr}$, confirming a previous limit on $d\alpha/dt$ and providing the most stringent limit on $d \mu/dt$ from laboratory experiments.