论文标题
部分可观测时空混沌系统的无模型预测
Upgrade and commissioning of the ALICE muon spectrometer
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
ALICE (A Large Ion Collider Experiment) at the CERN Large Hadron Collider (LHC) is designed to study proton-proton and heavy-ion collisions at ultra-relativistic energies. The main goal of the experiment is to assess the properties of quark gluon plasma, a state of matter where quarks and gluons are de-confined, reached in extreme conditions of temperature and energy density. During the ongoing long shutdown 2 of LHC, ALICE is undergoing a major upgrade of its apparatus, in view of the LHC Run 3, scheduled to start in 2022. The upgrade will allow a new ambitious programme of high-precision measurements to be deployed. Moreover, the detectors will have to cope with an increased collision rate, which will go up to 50 kHz in Pb-Pb collisions. For the muon spectrometer (MS) ALICE is implementing new hardware and software solutions. The installation of a new vertex tracker, the Muon Forward Tracker (MFT), in the acceptance of the MS will improve present measurements and enable new ones. It will allow one to separate, for the first time in ALICE in the forward-rapidity region, the prompt and non-prompt contributions to the cross-sections of charmonia. The matching of the muon tracks reconstructed in the MFT with those in the MS will add vertexing capabilities covering a broad range of transverse momenta down to pT = 0 and will improve significantly the invariant mass resolution, allowing for a better separation of the J/psi and psi(2S) states. In addition, the front-end and readout electronics of the muon tracking system (cathode pad chambers) and of the muon identification system (resistive plate chambers) will be upgraded, in order to optimize the detector performance in the new running conditions. A detailed description of the MS upgrades, together with the results from the commissioning with cosmic rays and the first LHC beams, will be presented in this talk.
