标题： $h \to Υγ$衰变：错误符号的$hb\bar{b}$耦合的决定性特征 显示英文标题

标题： $h \to Υγ$ Decay: Smoking Gun Signature of Wrong-Sign $hb\bar{b}$ Coupling

摘要： 我们以与模型无关的方式分析利用希格斯粒子衰变为$\Upsilon \gamma$探测新物理的潜力。 在标准模型中，$h \to \Upsilon \gamma$的衰变宽度异常小，这是由于直接和间接衰变图之间的意外抵消。 因此，任何能够改变直接或间接衰变振幅的新物理都会破坏标准模型中的意外抵消，并可能导致$h \to \Upsilon \gamma$的衰变宽度相对较大。 在此，我们进行了一项详细的与模型无关的分析，研究可能破坏这种抵消的新物理。 我们证明，在考虑了实验测量对希格斯粒子产生和衰变过程的所有可能约束后，只有反号$h b \bar{b}$耦合的情况可以使$h \to \Upsilon \gamma$的衰变宽度变化近两个数量级。 我们得出结论，如果在大型强子对撞机或任何未来的对撞机上观察到显著增强的$h \to \Upsilon \gamma$衰变宽度，这将是反号$h b \bar{b}$耦合的决定性证据。 显示英文摘要

摘要： We analyze in a model-independent way the potential to probe new physics using Higgs decay to $\Upsilon \gamma$. The $h \to \Upsilon \gamma$ decay width is unusually small in the Standard Model because of an accidental cancellation among the direct and indirect decay diagrams. Thus, any new physics that can modify the direct or the indirect decay amplitudes disrupts the accidental Standard Model cancellation and can potentially lead to a relatively large decay width for $h \to \Upsilon \gamma$. Here, we carry out a detailed model-independent analysis of the possible new physics that can disrupt this cancellation. We demonstrate that after taking into account all possible constraints on Higgs production and decay processes from experimental measurements, the wrong-sign $h b \bar{b}$ coupling is the only scenario in which the $h \to \Upsilon \gamma$ decay width can be changed by almost two orders of magnitude. We conclude that an observation of a significantly enhanced $h \to \Upsilon \gamma$ decay width at the LHC or any future collider will be a conclusive evidence of a wrong-sign $h b \bar{b}$ coupling.