Full Jet Reconstruction In Relativistic Heavy Ion Collisions

量子色动力学（QCD）是强作用力的基础理论，它预测夸克和胶子的解放会产生一个新的物质相——夸克胶子等离子体（QGP）。在过去的10年里，在相对论重离子对撞机（RHIC）上进行的实验验证了这一预测，并探索了这种新型物质的特性。虽然对QCD计算的天真解释表明，在RHIC产生的QGP应该表现得像一种稀释的气体，但实验结果提供的证据表明，它的行为更像是一种近乎“完美”的液体，对有色部分子的通过是不透明的。2010年11月，大型强子对撞机成功地以前所未有的2.76 TeV的质心能量进行了第一次重离子碰撞，以探索相图的新区域。在大型强子对撞机的广泛扩展的运动范围内，各种各样的高能硬探针测量将是可用的。这些新的测量将量化QGP的基本性质。这一建议的知识价值源于PI将硬探针作为诊断工具来确定热QCD物质的详细属性。为了获得更完整、定量和有区别的彩色部分猝灭图像，并避免主要强子测量的固有偏差，PI将使用CMS探测器重建LHC相对论重离子碰撞中的射流。她建议将QGP的大颜色不透明度的知识转化为通过测量射流结构来确定其基本性质，并通过无偏全射流重建来测量射流的核修饰比。通过这些可靠的测量，她将确定QGP的关键特征，例如热QCD介质对射流能量损失的反应以及QGP如何影响射流结构。为了使该项目产生更广泛的影响，PI计划通过积极的研究和教育相结合，为核物理学的多样化和竞争性劳动力建立一个培养环境。她将在夏季学期从罗格斯大学的阿雷斯蒂项目中招募并指导两名少数族裔和女性大三本科生，并继续为他们提供全年的支持。她计划让这些本科生参与研究的所有阶段，包括数据采集、分析、在会议上展示结果，以及撰写评审论文。

Quantum chromodynamics (QCD), the fundamental theory of the strong force, predicts the liberation of quarks and gluons to create a new phase of matter, the Quark Gluon Plasma (QGP). During the last 10 years, experiments performed at the Relativistic Heavy Ion Collider (RHIC) tested this prediction and explored the properties of this novel form of matter. While the naive interpretations of QCD calculations suggested that this QGP produced at RHIC should behave like a dilute gas, the experimental results provided evidence that it behaves more like a nearly `perfect' liquid, which is opaque to the passage of colored partons. In November 2010, LHC successfully delivered the first heavy ion collisions at an unprecedented center-of-mass energy of 2.76 TeV to explore new regions of the phase diagram. A wide variety of energetic hard probe measurements will be available over a broad extended kinematic range at LHC. These new measurements will quantify the fundamental properties of QGP.The intellectual merit of this proposal derives from the PI's focus on hard probes as a diagnostic tool to determine the detailed properties of the hot QCD matter. For a more complete, quantitative and discriminatory picture of quenching of the color partons and to avoid intrinsic biases of leading hadron measurements, the PI will reconstruct jets in relativistic heavy ion collisions at LHC using the CMS detector. She proposes to transform knowledge of the large color opaqueness of the QGP to the determination of its fundamental properties by the measurements of jet structure and its modification in terms of energy flow by an unbiased full jet reconstruction to measure nuclear modification ratios of jets. With these robust measurements, she will determine key features of QGP such as how hot QCD medium responds to jet energy loss and how QGP affects jet structures. For broader impacts of this project, the PI plans to establish a cultivating environment for a diverse and competitive work force in nuclear physics via integration of active research and education. She will recruit and mentor two minority and female junior undergraduates from Rutgers's Aresty program for the summer term and continue supporting them throughout the year. She plans to include these undergraduates in all phases of research, including data taking, analysis, presentation of results at meetings, and writing refereed papers.