论文标题
希格斯腐烂与di-photon处的分支比的预期测量精度
The expected measurement precision of the branching ratio of the Higgs decaying to the di-photon at the CEPC
论文作者
论文摘要
本文介绍了在3 $ z $ decay Channels中衡量$σ（e^{+} e^{ - } \ to zh）\ times br（h \toγγ）$的前景GEV $在圆形电子碰撞器（CEPC）处。生成模拟的蒙特卡洛事件，并缩放为5.6 $ ab^{ - 1} $的集成光度，以模仿数据。还显示了推断为20 $ ab^{ - 1} $的结果。结合3个$ z $玻色子衰减的3个频道后，此测量的预期统计精度为7.7 \％。有了对系统不确定性的一些初步估计，总精度为7.9 \％。通过在$ e^{+} e^{+} e^{ - } \ to zh \ to q \ bar {q}γγγ$通道中涂抹光子能量分辨率，研究了CEPC电磁热量计的性能（ECAL）。在目前的ECAL设计中，分辨率的随机项在$ H \至γγ$通道的HigGS测量精度中起主要作用。研究分辨率对$σ（ZH）\ times br（ZH \ to q \ bar {q}γγ）$的测量精度以及ECAL常数项和随机项的优化，以进行进一步的检测器设计。
This paper presents the prospects of measuring $σ(e^{+}e^{-}\to ZH)\times Br(H \to γγ)$ in 3 $Z$ decay channels $Z \to q\bar{q} / μ^{+} μ^{-} / ν\barν$ using the baseline detector with $\sqrt{s} = 240 GeV$ at the Circular Electron Positron Collider (CEPC) . The simulated Monte Carlo events are generated and scaled to an integrated luminosity of 5.6 $ab^{-1}$ to mimic the data. Extrapolated results to 20 $ab^{-1}$ are also shown. The expected statistical precision of this measurement after combining 3 channels of $Z$ boson decay is 7.7\%. With some preliminary estimation on the systematical uncertainties, the total precision is 7.9\%. The performance of CEPC electro-magnetic calorimeter (ECAL) is studied by smearing the photon energy resolution in simulated events in $e^{+}e^{-} \to ZH \to q\bar{q}γγ$ channel. In present ECAL design, the stochastic term in resolution plays the dominant role in the precision of Higgs measurements in $H \to γγ$ channel. The impact of the resolution on the measured precision of $σ(ZH)\times Br(ZH \to q\bar{q}γγ)$ as well as the optimization of ECAL constant term and stochastic term are studied for the further detector design.
