Enhancement of hyperon production at central rapidity in 158<i>A</i>GeV/<i>c</i>Pb–Pb collisionsF. Antinori, P A Bacon, A. Badalà et al.|Journal of Physics G Nuclear and Particle Physics|2006 Results are presented on hyperon and antihyperon production in Pb-Pb, pPb and pBe collisions at 158 GeV/c per nucleon. Lambda, Xi and Omega yields have been measured at central rapidity and medium transverse momentum as functions of the centrality of the collision. Comparing the yields in Pb-Pb to those in pBe interactions, strangeness enhancement is observed. The enhancement increases with the centrality and with the strangeness content of the hyperons, reaching a factor of about 20 for the Omega in the central Pb-Pb collisions.
The ALICE data acquisition systemF. Carena, W. Carena, S. Chapeland et al.|Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment|2013 In this paper we describe the design, the construction, the commissioning and the operation of the Data Acquisition (DAQ) and Experiment Control Systems (ECS) of the ALICE experiment at the CERN Large Hadron Collider (LHC). The DAQ and the ECS are the systems used respectively for the acquisition of all physics data and for the overall control of the experiment. They are two computing systems made of hundreds of PCs and data storage units interconnected via two networks. The collection of experimental data from the detectors is performed by several hundreds of high-speed optical links. We describe in detail the design considerations for these systems handling the extreme data throughput resulting from central lead ions collisions at LHC energy. The implementation of the resulting requirements into hardware (custom optical links and commercial computing equipment), infrastructure (racks, cooling, power distribution, control room), and software led to many innovative solutions which are described together with a presentation of all the major components of the systems, as currently realized. We also report on the performance achieved during the first period of data taking (from 2009 to 2013) often exceeding those specified in the DAQ Technical Design Report.
Silicon pixel detectors for tracking in NA57V. Manzari, F. Antinori, A. Badalà et al.|Nuclear Physics A|1999 40 A GeV/c Pb-Pb衝突における中心ラピディティのストレンジネス増大F. Antinori, P A Bacon, A. Badalà et al.|Journal of Physics G Nuclear and Particle Physics|2010 The ALICE Electronic LogbookV. Altini, F. Carena, W. Carena et al.|Journal of Physics Conference Series|2010 All major experiments need tools that provide a way to keep a record of the events and activities, both during commissioning and operations. In ALICE (A Large Ion Collider Experiment) at CERN, this task is performed by the Alice Electronic Logbook (eLogbook), a custom-made application developed and maintained by the Data-Acquisition group (DAQ). Started as a statistics repository, the eLogbook has evolved to become not only a fully functional electronic logbook, but also a massive information repository used to store the conditions and statistics of the several online systems. It's currently used by more than 600 users in 30 different countries and it plays an important role in the daily ALICE collaboration activities. This paper will describe the LAMP (Linux, Apache, MySQL and PHP) based architecture of the eLogbook, the database schema and the relevance of the information stored in the eLogbook to the different ALICE actors, not only for near real time procedures but also for long term data-mining and analysis. It will also present the web interface, including the different used technologies, the implemented security measures and the current main features. Finally it will present the roadmap for the future, including a migration to the web 2.0 paradigm, the handling of the database ever-increasing data volume and the deployment of data-mining tools.