The FairRoot framework Al-Turany, M; Bertini, D; Karabowicz, R ...
Journal of physics. Conference series,
01/2012, Letnik:
396, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The FairRoot framework is an object oriented simulation, reconstruction and data analysis framework based on ROOT. It includes core services for detector simulation and offline analysis. The ...framework delivers base classes which enable the users to easily construct their experimental setup in a fast and convenient way. By using the Virtual Monte Carlo concept it is possible to perform the simulations using either Geant3 or Geant4 without changing the user code or the geometry description. Using and extending the task mechanism of ROOT it is possible to implement complex analysis tasks in a convenient way. Moreover, using the FairCuda interface of the framework it is possible to run some of these tasks also on GPU. Data IO, as well as parameter handling and data base connections are also handled by the framework. Since some of the experiments will not have an experimental setup with a conventional trigger system, the framework can handle also free flowing input streams of detector data. For this mode of operation the framework provides classes to create the needed time sorted input streams of detector data out of the event based simulation data. There are also tools to do radiation studies and to visualize the simulated data. A CMake-CDash based building and monitoring system is also part of the FairRoot services which helps to build and test the framework on many different platforms in an automatic way, including also Continuous Integration.
FairRoot is the simulation and analysis framework used by CBM and PANDA experiments at FAIR/GSI. The use of graphics processor units (GPUs) for event reconstruction in FairRoot will be presented. The ...fact that CUDA (Nvidia's Compute Unified Device Architecture) development tools work alongside the conventional C/C++ compiler, makes it possible to mix GPU code with general-purpose code for the host CPU, based on this some of the reconstruction tasks can be send to the graphic cards. Moreover, tasks that run on the GPU's can also run in emulation mode on the host CPU, which has the advantage that the same code is used on both CPU and GPU.
The proposed project FAIR (Facility for Anti-proton and Ion Research) is an international accelerator facility of the next generation. It builds on top of the experience and technological ...developments already made at the existing GSI facility, and incorporate new technological concepts. The four scientific pillars of FAIR are NUSTAR (nuclear structure and astrophysics), PANDA (QCD studies with cooled beams of anti-protons), CBM (physics of hadronic matter at highest baryon densities), and APPA (atomic physics, plasma physics, and applications). The FairRoot framework used by all of the big FAIR experiments as a base for their own specific developments, provides basic functionality like IO, geometry handling etc. The challenge is to support all the different experiments with their heterogeneous requirements. Due to the limited manpower, one of the first design decisions was to (re)use as much as possible already available and tested software and to focus on the development of the framework. Beside the framework itself, the FairRoot core team also provides some software development tools. We will describe the complete set of tools in this article. The Makefiles for all projects are generated using CMake. For software testing and the corresponding quality assurance, we use CTest to generate the results and CDash as web front end. The tools are completed by subversion as source code repository and trac as tool for the complete source code management. This set of tools allows us to offer the full functionality we have for FairRoot also to the experiments based on FairRoot.
We present a measurement of π−/π+, K−/K+ and p¯/p from p+p collisions at s=200 GeV over the rapidity range 0<y<3.4. For pT<2.0 GeV/c we see no significant transverse momentum dependence of the ...ratios. All three ratios are independent of rapidity for y≲1.5 and then steadily decline from y∼1.5 to y∼3. The π−/π+ ratio is below unity for y>2.0. The p¯/p ratio is very similar for p+p and 20% central Au+Au collisions at all rapidities. In the fragmentation region the three ratios seem to be independent of beam energy when viewed from the rest frame of one of the protons. Theoretical models based on quark–diquark breaking mechanisms overestimate the p¯/p ratio up to y≲3. Including additional mechanisms for baryon number transport such as baryon junctions leads to a better description of the data.
Herewith we present the production of identified hadrons in Au+Au and p+p collisions at
s
N
N
=
200
GeV
at forward rapidity,
y
≈
3.2
. Suppression of pions and kaons and enhancement for protons in ...central Au+Au collisions is observed. These results are found to be very similar in strength to that observed at mid-rapidity. Furthermore, we see a gradual decrease of the observed suppression towards more peripheral collisions.
We review the main results obtained by the BRAHMS Collaboration on the properties of hot and dense hadronic and partonic matter produced in ultrarelativistic heavy ion collisions at RHIC. A ...particular focus of this paper is to discuss to what extent the results collected so far by BRAHMS, and by the other three experiments at RHIC, can be taken as evidence for the formation of a state of deconfined partonic matter, the so-called quark–gluon plasma (QGP). We also discuss evidence for a possible precursor state to the QGP, i.e., the proposed color glass condensate.
Scanning the phases of QCD with BRAHMS Murray, Michael; Collaboration, the BRAHMS
Journal of Physics G: Nuclear and Particle Physics,
08/2004, Letnik:
30, Številka:
8
Journal Article, Conference Proceeding
Transverse momentum spectra of protons and anti-protons measured in the rapidity range 0<y<3.1 from 0–10% central Au+Au collisions at sNN=62.4 GeV are presented. The rapidity densities, dN/dy, of ...protons, anti-protons and net-protons (Np–Np¯) have been deduced from the spectra over a rapidity range wide enough to observe the expected maximum net-baryon density. From mid-rapidity to y=1 the net-proton yield is roughly constant (dN/dy∼10), but rises to dN/dy∼25 at 2.3<y<3.1. The mean rapidity loss is 2.01±0.14±0.12 units from beam rapidity. The measured rapidity distributions are compared to model predictions. Systematics of net-baryon distributions and rapidity loss vs. collision energy are discussed.
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