arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新，休息一下吧，周末愉快~~
arXiv 2604.24924hep-phhep-ex
收藏

τ⁻→Kπν_τ中 forward backward CP 不对称性在左-右反锯齿模型中的研究

Forward backward CP asymmetry in $τ^- \to K πν_τ$ in the Left-Right Inverse seesaw model

Universidad de Guanajuato（瓜纳华托大学）；Zewail City of Science and Technology（泽维尔科学技术城）

David Delepine, Shaaban Khalil

备注：
24 pages, 3 figures
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

研究左-右反锯齿模型中τ⁻→Kπν_τ衰变的CP破坏效应，发现尽管积分不对称性不足以解释BaBar结果，但模型预测了显著的微分正反向CP不对称性信号。

摘要：

最近BaBar合作组对τ→Kπν_τ衰变的积分CP不对称性测量显示与标准模型预测有2.8σ偏差。本文在左-右反锯齿模型中研究CP破坏效应。我们证明尽管积分不对称性仍太小无法解释BaBar结果，但模型预测了显著的微分正反向CP不对称性信号A_{CP}^{FB}(s)。我们推导了相关衰变的有效|ΔS|=1哈密顿量，并识别出由重中微子和标量交换参与的顶夸克味改变中性电流盒图生成的主导非退耦标量算符g_S。数值分析显示，尽管这一贡献在积分A_{CP}中大部分抵消，但通过与标准模型向量电流的干涉显著增强A_{CP}^{FB}(s)，导致K*(892)和K_0*(1430)共振附近出现显著的动量学特征。这些角和微分可观测量为当前和未来风味实验（特别是Belle~II）提供了对LRIS标量部分的灵敏探测。

英文摘要：

The Left--Right Inverse Seesaw (LRIS) model, in which TeV-scale right-handed neutrinos can carry $\mathcal{O}(1)$ Yukawa couplings while light neutrino masses remain protected by a small lepton-number-violating scale, provides a testable link between the neutrino-mass mechanism and flavor and collider observables: the same non-decoupling dynamics has recently been shown to enable viable TeV-scale non-thermal leptogenesis and to explain the $B\to Kμ^+μ^-$ anomaly. Here we examine a further, independent test of the same scalar sector in the semileptonic decay $τ\to Kπν_τ$. We identify a distinct, unsuppressed signal in the \emph{differential} forward-backward CP asymmetry $A_{\rm CP}^{\rm FB}(s)$, driven by interference between the SM vector current and a non-decoupling scalar operator $g_S$ generated by a top-quark flavor-changing neutral-current box diagram with internal heavy neutrinos and charged Goldstone bosons. We derive the effective $|ΔS|=1$ Hamiltonian, verify consistency with $K^0$--$\bar K^0$ and $B_d^0$--$\bar B_d^0$ mixing, $B\to X_sγ$, and neutrino non-unitarity constraints, and show numerically that $A_{\rm CP}^{\rm FB}(s)$ is resonantly enhanced near the $K_0^*(1430)$ state, reaching $\mathcal{O}(10^{-4})$ -- within reach of Belle~II.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑