arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1105.0364hep-phhep-ex
收藏

辐射B介子衰变中的反常$tqγ$耦合效应

Anomalous $tqγ$ coupling effects in exclusive radiative B-meson decays

Xin-Qiang Li, Ya-Dong Yang, Xing-Bo Yuan

备注：
25 pages, 15 figures, pdflatex
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

在CERN LHC上将寻找顶夸克FCNC过程，它与B介子衰变相关。本文研究了顶夸克反常相互作用$tqγ$在排斥辐射$B\to K^*γ$和$B\toργ$衰变中的作用。利用目前的实验数据，分别导出了由$B\to K^*γ$衰变产生的耦合$κ_{tcR}^γ$和由$B\to ργ$衰变产生的耦合$κ_{tuR}^γ$的边界.来自${\mathcal B}(B\to K^{*}γ)$的$|κ_{tcR}^γ|$上的结合通常与来自${\mathcal B}(B\to X_{s}γ)$的结合相容。然而，由于$Δ(K^{*}γ)$的同位旋不对称性，进一步限制了$κ_{tcR}^γ$的位相，并且结合束缚导致了上限$\mathcal B(t\to cγ)<0.21%$，低于CDF的结果.对于真正的$κ_{tcR}^γ$，$\mathcal B(t\to cγ)$的上限大约与ATLAS的$5σ$发现潜力相同，其积分光度为$10 {\rm fb}^{-1}$。对于$B\toργ$衰变，NP的贡献被一个大的CKM因子$|V_{ud}/V_{td}|$增强，并且对$tuγ$耦合的约束是相当限制性的，$\mathcal B(t\to uγ)<1.44\times 10^{-5}$。随着LHCb和未来的超级B工厂的精确测量，我们可以得到$B\to V γ$和罕见的$t\to qγ$衰变之间的密切相关性，这将直接在LHC ATLAS和CMS上进行研究。

英文摘要：

The top-quark FCNC processes will be searched for at the CERN LHC, which are correlated with the B-meson decays. In this paper, we study the effects of top-quark anomalous interactions $tqγ$ in the exclusive radiative $B\to K^*γ$ and $B\toργ$ decays. With the current experimental data of the branching ratios, the direct CP and the isospin asymmetries, bounds on the coupling $κ_{tcR}^γ$ from $B\to K^*γ$ and $κ_{tuR}^γ$ from $B\to ργ$ decays are derived, respectively. The bound on $|κ_{tcR}^γ|$ from ${\mathcal B}(B\to K^{*}γ)$ is generally compatible with that from ${\mathcal B}(B\to X_{s}γ)$. However, the isospin asymmetry $Δ(K^{*}γ)$ further restrict the phase of $κ_{tcR}^γ$, and the combined bound results in the upper limit, $\mathcal B(t\to cγ)<0.21%$, which is lower than the CDF result. For real $κ_{tcR}^γ$, the upper bound on $\mathcal B(t\to cγ)$ is about of the same order as the $5σ$ discovery potential of ATLAS with an integrated luminosity of $10 {\rm fb}^{-1}$. For $B\toργ$ decays, the NP contribution is enhanced by a large CKM factor $|V_{ud}/V_{td}|$, and the constraint on $tuγ$ coupling is rather restrictive, $\mathcal B(t\to uγ)<1.44\times 10^{-5}$. With refined measurements to be available at the LHCb and the future super-B factories, we can get close correlations between $B\to V γ$ and the rare $t\to qγ$ decays, which will be studied directly at the LHC ATLAS and CMS.

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。

↑