论文标题
$ {\ cal b} r（h \ tozγ）$的测量在250 GEV ILC
Measurement of ${\cal B}r(H \to Zγ)$ at the 250 GeV ILC
论文作者
论文摘要
研究了$ e^+e^ - \ to Hz $进程，随后的Higgs Boson $ H \ toZγ$的衰减进行了研究，在此，两个$ Z $玻色子都在最终的状态中重建了两个喷气机。使用Monte Carlo数据样本进行分析，以详细的ILD（国际大探测器）探测器模拟获得，假设集成的亮度为2 ab $^{ - 1} $，$ {\ cal {p}}} _ {p}} _ {e^-e^-e^-e^ +} =（e^-e^ +} =（ - 0.8，+0.8，+0.3）$ y的光束极化250 GEV。对于两个0.9 ab $^{ - 1} $数据样本的情况，重复分析的情况，$ {\ cal {p}} _ {e^-e^+} =（\ mp0.8，\ pm0.3）$。使用所有可用的ILD MC事件样本研究了潜在背景过程的贡献。最大的背景来自$ e^+e^ - \ to w^+w^ - $ $过程，该过程补充了由初始状态辐射产生的能量光子。为了抑制这种背景，我们要求至少$ z $玻色子中的至少一个腐烂到$ b $ jets。为了减少喷气重建不确定性，使用$m_δ= m（jjγ）-M（JJ） + m（z _ {\ rm nom}）$变量，其中$ m（z _ {\ rm nom}）$ = 91.2 gev。为研究的信号和背景获得了$M_δ$分布，以估算$ {\ cal b} r（h \ tozγ）$测量的预期准确性。对于上述单个极化样本的选项，准确性为22 $ \％$，在样本带有两个极化的情况下，其精度为24 $ \％$。提出的方法可以在未来的任何$ e^+e^ - $ collider上应用。
The $e^+e^- \to HZ$ process with the subsequent decay of the Higgs boson $H \to Zγ$ is studied, where both $Z$ bosons are reconstructed in the final states with two jets. The analysis is performed using Monte Carlo data samples obtained with detailed ILD (The International Large Detector) detector simulation assuming an integrated luminosity of 2 ab$^{-1}$, beam polarizations of ${\cal{P}}_{e^-e^+} = (-0.8, +0.3)$, and center-of-mass energy of $\sqrt{s}$ = 250 GeV. The analysis is repeated for the case of two 0.9 ab$^{-1}$ data samples with polarizations ${\cal{P}}_{e^-e^+} = (\mp0.8, \pm0.3)$. Contributions of the potential background processes are studied using all available ILD MC event samples. The largest background comes from the $e^+e^- \to W^+W^-$ process supplemented by an energetic photon produced by initial state radiation. To suppress this background we require that at least one of the $Z$ bosons decays to $b$-jets. To reduce the jet reconstruction uncertainties the $M_Δ = M(jjγ) - M(jj) + M(Z_{\rm nom})$ variable is used, where $M(Z_{\rm nom})$ = 91.2 GeV. The $M_Δ$ distributions are obtained for the studied signal and backgrounds to estimate the expected accuracy of the ${\cal B}r(H \to Zγ)$ measurement. The accuracy is 22$\%$ for the option of the single polarization sample described above and deteriorate to 24$\%$ in case of the sample with two polarizations. The proposed method can be applied at any future $e^+e^-$ collider.
