New measurement of Lambda-c production in Pb-Pb collisions with the Alice experiment at the LHC

LHC 的 Alice 实验对 Pb-Pb 碰撞中 Lambda-c 产生的新测量

• 批准号: 2275038
• 金额: --
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2275038
• 关键词: New; measurement; Lambda; production; Pb

ALICE (A Large Ion Collider Experiment) is one of the four main experiments at the LHC (CERN, Geneva), whose physics programme focuses on heavy-ion collision measurements. Under extreme conditions of temperature and/or density, hadronic matter 'melts' into a plasma of 'free' quarks and gluons - the so-called quark-gluon plasma (QGP). This was the state of the Early Universe a few microseconds after the Big Bang. To create these conditions in the laboratory, heavy ions (Pb nuclei) are accelerated and made to collide head on at unprecedented energies. Open heavy-flavour production is one of the most valuable probes to measure properties of the dense QCD medium formed in heavy-ion collisions at the LHC. Heavy quarks, once produced in the early stages of the collision, are expected to re-scatter and lose energy while traversing the surrounding matter, carrying important information on the properties of the hot medium. First preliminary measurements using the current ALICE detector have been made recently of D meson and Ac baryon production in pp, p-Pb and Pb-Pb collisions, though with limited statistics and resolution.The PhD project aims to develop an analysis strategy to extract for the first time the Ac baryon signal from the decay channel into pKn, in the high multiplicity environment of the 5 TeV Pb-Pb collisions at the LHC. This will be done while developing state-of-the-art machine learning analyses tools. The student will then estimate the necessary corrections and measure the pT-differential production cross-section of the charmed baryon and determine the systematic errors associated with this new measurement.

大型离子对撞机实验(ALICE)是欧洲核子研究中心(CERN，日内瓦)的四个主要实验之一，其物理计划侧重于重离子碰撞测量。在极端的温度和/或密度条件下，强子物质“熔化”成由“自由”夸克和胶子组成的等离子体，即所谓的夸克-胶子等离子体(QGP)。这是宇宙大爆炸后几微秒内早期宇宙的状态。为了在实验室中创造这些条件，重离子(铅核)被加速，并以前所未有的能量迎头相撞。开放的重味产生是测量大型强子对撞机重离子碰撞中形成的致密QCD介质性质的最有价值的探测器之一。重夸克一旦在碰撞的早期阶段产生，预计会在穿越周围物质时重新散射和损失能量，携带着关于热介质性质的重要信息。最近，利用目前的ALICE探测器首次对pp、p-pb和pb-pb碰撞中的D介子和交流重子的产生进行了初步测量，但统计和分辨率有限。PHD项目的目标是开发一种分析策略，首次在大型强子对撞机5TeV铅-铅碰撞的高重数环境中从衰变通道中提取交流重子信号到PKN中。这将在开发最先进的机器学习分析工具时完成。然后，学生将估计必要的修正，测量迷人重子的PT-微分产生截面，并确定与此新测量相关的系统误差。