论文标题
对$ZγV^\ ast $顶点的非对角线贡献，$ z \ overline {t} q $耦合的极化和界限
Non-diagonal contributions to $ZγV^\ast$ vertex, polarizations and bounds on $Z\overline{t}q$ couplings
论文作者
论文摘要
我们研究了一环级别的三线性中性仪表玻色子耦合$zγV^\ ast $（$ v = z $，$γ$）的中性中性当前贡献。仅引起$ CP $ -CON-CONSERVING FORMARVING $ H_3^Z $，其相关贡献来自顶级夸克耦合。在我们的数值分析中，对$ z \ overline {t} q $（$ q = c $，$ u $）耦合的约束是从当前LHC数据中获得的，导致$ | g _ {\ g _ {\ text {v}}}}}^{tu}^{tu} | 0.007 $和$ | g _ {\ text {v}}^{tc} | \ text {，} | g _ {\ text {a}}^{tc} | \ leqslant 0.0095 $用于矢量和轴向couplings。 $ h_3^z $ form form的新贡献是$ 10^{ - 7} $的订单。此外，我们分析了$ v^\ ast \ rightarrowZγ$过程的两极分化部分衰减宽度，还讨论了一种新型的左右不对称性。我们发现，在存在新物理学的情况下，极化$γ（v^\ ast \ rightarrowZγ）$表现出与SM预测的显着偏差，导致非零的不对称性。
We study the flavor-changing neutral current contributions to the trilinear neutral gauge boson couplings $ZγV^\ast$ ($V=Z$, $γ$) at the one-loop level. Only the $CP$-conserving form factor $h_3^Z$ is induced, with the relevant contributions arising from top quark couplings. To our numerical analysis, constraints on the $Z\overline{t}q$ ($q=c$, $u$) couplings are obtained from current LHC data, leading to bounds of $|g_{\text{V}}^{tu}|\text{,}|g_{\text{A}}^{tu}|\leqslant 0.007$ and $|g_{\text{V}}^{tc}|\text{,}|g_{\text{A}}^{tc}|\leqslant 0.0095$ for the vector and axial couplings. The new contributions to the $h_3^Z$ form factor are of order $10^{-7}$. Furthermore, we analyze the polarized partial decay widths of the $V^\ast\rightarrow Zγ$ process, and a new type of left-right asymmetry is also discussed. We find that in the presence of new physics, the polarized $Γ(V^\ast\rightarrow Zγ)$ exhibits significant deviations from the SM prediction, resulting in a non-zero asymmetry.
