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arXiv 0705.2740hep-ex
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在\sqrt{s} =14 TeV下CMS实验中直接光子加喷流产生的研究

Study of Direct Photon plus Jet production in CMS Experiment at \sqrt{s}=14 TeV

Pooja Gupta, B. C. Choudhary, S. Chatterji, S. Bhattacharya

摘要:

本文介绍了在大型强子对撞机(LHC)质心能量$\sqrt{s}$ =14 TeV下,利用CMS(Compact Muon Solenoid)面向对象软件对$γ$ +喷流分析的模拟结果。直接光子产生的研究有助于验证微扰量子色动力学(pQCD),并提供有关核子中胶子分布的信息。直接光子过程也构成了其他几个标准模型(SM)过程和新物理信号的主要背景。因此,这些过程需要在新的能源制度中得到准确的理解。在这项工作中,我们已经做了详细的研究GEANT 4模拟$γ$ +喷流事件与Pythia产生的,以及相关的背景过程。隔离切割已经针对直接光子进行了优化,与之前在CMS中进行的研究相比,其通过$\sim25%$提高了信号与背景的比率。在分析中,在光子和$40^0$处的领先喷流之间包含大的$Δϕ$切割,导致S/B中的$\sim15%$进一步增加,从而给出S/B比中的$\sim42%$的总体增益。

英文摘要:

We present simulation results of $γ$ + Jet analysis using CMS (Compact Muon Solenoid) Object-Oriented software at the Large Hadron Collider (LHC) center of mass energy $\sqrt{s}$=14 TeV. The study of direct photon production helps in validating the perturbative Quantum Chromodynamics (pQCD) and providing information on the gluon distribution in the nucleons. Direct photon processes also constitute a major background to several other Standard Model (SM) processes and signals of new physics. Thus these processes need to be understood precisely in the new energy regime. In this work, we have done a detailed study of the GEANT4 simulated $γ$ + jet events generated with Pythia, and the related background processes. Isolation cuts have been optimized for direct photon which improves the signal over background ratio by $\sim25%$ as compared to previous studies done in CMS. The inclusion of a large $Δϕ$ cut between the photon and the leading jet at $40^0$ in the analysis leads to a further increase of $\sim15%$ in S/B, thus giving an overall gain of $\sim42%$ in S/B ratio.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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