Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

大規模ハドロン衝突型加速器実験におけるトリガー・データ収集系の物理への影響とALICE実験における新規検出器制御監視系

広島大学(Hiroshima University)博士(理学)Doctor of Sciencedoctora

The Detector Control System of the Muon Forward Tracker for the ALICE Experiment at LHC

ALICE is the LHC experiment specifically devoted to the study of heavy-ion collisions. The Muon Forward Tracker (MFT) is one of the new detectors developed in the framework of the upgrade programs towards the LHC Run 3 starting from 2021. A Detector Control System (DCS) was developed for the MFT within the new framework of the upgraded ALICE central DCS. In this framework, detectors will deliver physics raw data as well as slow control data. The central DCS will be composed of an interface, named Alice Low level FRont-End Device (ALFRED), to convert high-level words within the DCS to low-level words which are sent to the detector FEE as commands. Used Supervisory Control And Data Acquisition (SCADA) is WinCC Open Architecture (OA). In addition, Joint Control Project Framework is installed to provide standard DCS solutions such as a Finite State Machine (FSM) commonly used by the LHC experiments. The FSM, as a base of the DCS hierarchy, was fully developed and successfully tested. A test bench of the MFT DCS was built as a minimal setup of the full DCS chain consisting of WinCC OA, ALFRED, a demonstration board of a DCS chip and a readout board. The latest status will be presented