标题： 原子炼金术 显示英文标题

标题： Atomic Alchemy

摘要： 我们考虑电磁束缚态之间的跃迁，例如缪子原子专一性弱衰变到电子原子： $(\mu^- Z) \to (e^- Z) {\bar \nu_e }\nu_\mu . $ 我们表明，原子波函数中的相对论效应对于确定衰变率是至关重要的。 在重原子的情况下，专一性通道的分支比超过 $10^{-6},$，这可能使这些稀有衰变的研究处于实验可探测的范围内。 此类过程因此为研究原子物理中波函数的高动量尾部提供了一个详细的实验室；此外，它们还为研究量子色动力学中类似的专一性重强子衰变提供了一个简单的模型，例如 $B \to \pi e \nu.$ 显示英文摘要

摘要： We consider the transitions between electromagnetic bound states, such as the exclusive weak decay of a muonic atom into an electronic atom: $(\mu^- Z) \to (e^- Z) {\bar \nu_e }\nu_\mu . $ We show that relativistic effects in the atomic wavefunctions are crucial for determining the rate. In the case of heavy atoms, the exclusive channel branching ratios exceed $10^{-6},$ possibly bringing the study of these rare decays within experimental reach. Such processes thus provide a detailed laboratory for studying the high momentum tail of wavefunctions in atomic physics; in addition, they provide a simple toy model for investigating analogous exclusive heavy hadronic decays in quantum chromodynamics such as $B \to \pi e \nu.$