CERN, Geneva, Switzerland.
Philos Trans A Math Phys Eng Sci. 2012 Feb 28;370(1961):917-32. doi: 10.1098/rsta.2011.0469.
After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.
经过近 20 年的筹备，专门的重离子实验——大型离子对撞机实验（ALICE）于 2009 年底在 CERN 大型强子对撞机（LHC）加速器中进行了首次质子碰撞实验，并于 2010 年底进行了铅核碰撞实验。本文在简要介绍了超相对论重离子碰撞物理学之后，回顾了探测器的主要设计选择，并总结了 ALICE 的初步运行和性能。该实验在运行的第一年主要集中于在 LHC 的新能量区域中，对典型的、平均的质子-质子（pp）和核-核反应的整体性质进行了研究。pp 的结果在不同程度上与大多数基于量子色动力学的唯象模型不同，为微调其参数提供了所需的输入。来自 pp 的初步结果与基于较低能量数据的预期基本一致，表明在 LHC 中产生的高密度物质虽然温度更高、体积更大，但仍然表现得像一种非常强相互作用的、近乎完美的液体。
