Probing the Hγγ coupling via Higgs boson exclusive decay into quarkonia plus a photon at the HL-LHC
Probing the Hγγ coupling via Higgs boson exclusive decay into quarkonia plus a photon at the HL-LHC
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DOI：
10.1103/physrevd.106.095013
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发表时间：
2022-08
影响因子：
5
通讯作者：
H. Dong;P. Sun;B. Yan
中科院分区：
文献类型：
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作者：
H. Dong;P. Sun;B. Yan
众所周知，精确测量$H\to\Gamma\Gamma$可以产生两个简并的参数空间，即$H\Gamma\Gamma$反常耦合。我们建议利用唯一的Higgs稀有衰变Hto Upsilon(Ns)+Gamma$来打破上述简并，进而约束HL-LHC上的$H\Gamma\Gamma$反常耦合。我们证明了在非类SM参数空间中，由于SM中直接和间接产生的$Upsilon(Ns)$之间的相消干涉，可以显著地提高$H对Upsilon(Ns)+Gamma$的分枝比。应用NRQCD因式分解方法，在非线性光学精度为$α_S$的情况下，计算了Hto(Ns)+Gamma的偏衰变宽度。结果表明，与ATLAS初步模拟相比，如果能进一步有效地抑制背景并提高信号效率，就有希望在HL-LHC打破这种简并的参数空间。
It is well know that the precise measurement of $H\to\gamma\gamma$ can generate two degenerate parameter spaces of $H\gamma\gamma$ anomalous coupling. We propose to utilize the exclusive Higgs rare decays $H\to\Upsilon(ns)+\gamma$ to break above mentioned degeneracy and further to constrain the $H\gamma\gamma$ anomalous coupling at the HL-LHC. We demonstrate that the branching ratios of $H\to\Upsilon(ns)+\gamma$ can be significantly enhanced in the non-SM-like parameter space from $H\to\gamma\gamma$ measurement, due to the destructive interference between the direct and indirect production of $\Upsilon(ns)$ in the SM. By applying the NRQCD factorization formalism, we calculate the partial decay widths of $H\to\Upsilon(ns)+\gamma$ at the NLO accuracy of $\alpha_s$. We show that it is hopeful to break such degenerate parameter space at the HL-LHC if we can further highly suppress the background and enhance the signal efficiency compared to the ATLAS preliminary simulation.