论文标题
间接CP违规对BR $（k_s \toμ^+μ^ - ）_ {\ ell = 0} $的影响
Impact of indirect CP violation on Br$(K_S \to μ^+μ^-)_{\ell=0}$
论文作者
论文摘要
decay $ k_s \ to（μ^+μ^ - ）_ {\ ell = 0} $，最终的muon对在零角度为零，是短途物理学的敏感探针。最近，已经显示了如何从中性的KAON衰减数据中提取该分支比率。我们指出，间接CP违规对此模式的标准模型预测的影响，而名义上是$ |ε_k| \ sim 10^{ - 3} $，通过较大的振幅比增强，并导致分支比br $（k_s \ toμ^+μ^ - ）_ {\ ell = 0} $的变化，取决于可以从数据中提取的相对相位的大小。我们还更新了短途贡献的标准模型预测。
The decay $K_S \to (μ^+μ^-)_{\ell=0}$, with the final muon pair in an angular-momentum zero state, is a sensitive probe of short-distance physics. It has recently been shown how to extract this branching ratio from neutral kaon decay data. We point out that the impact of indirect CP violation on the standard-model prediction of this mode, while nominally of order $|ε_K| \sim 10^{-3}$, is enhanced by a large amplitude ratio and leads to a shift of the branching ratio Br$(K_S \to μ^+μ^-)_{\ell=0}$ by a few percent, depending on the size of a relative phase that can be extracted from data. We also update the standard-model prediction of the short-distance contribution.
