Some new physics models of quantum gravity or dark matter predict drifts or oscillations of the fundamental constants. A relatively simple model relates molecular vibrations to the proton-to-electron mass ratio μ. Many vibrational transitions are at optical frequencies with prospects for use as highly accurate optical clocks. We give a brief summary of new physics models that lead to changes in μ and the current limits on drifts and oscillation amplitudes. After an overview of laboratory procedures, we give examples of molecules with experiments currently in development or underway. These experiments’ projected systematic and statistical uncertainties make them leading candidates in next-generation searches for time-variation of μ.

一些新的量子引力或暗物质物理学模型可以预测基本常数的漂移或振荡。一个相对简单的模型将分子振动与质子电子质量比μ关联起来。许多振动跃迁都在光频率处，并有望用作高度精确的光钟。我们简要总结了新的物理模型，这些模型会导致μ的变化以及漂移和振荡幅度的电流限制。在概述了实验室程序之后，我们给出了分子分子的例子，这些分子目前正在开发中或正在进行中。这些实验预计的系统和统计不确定性使它们成为下一代μ时变搜索的领先者。