1. |
- Aamodt, K., et al.
(author)
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The ALICE experiment at the CERN LHC
- 2008
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In: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Research review (peer-reviewed)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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2. |
- Averbeck, R., et al.
(author)
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The viscosity to entropy ratio from PHENIX data on single electron production
- 2008
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35
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Journal article (peer-reviewed)abstract
- The PHENIX experiment has measured electrons from the decay of hadrons carrying heavy flavor (charm or bottom quarks) in p + p and Au + Au collisions at at the Relativistic Heavy Ion Collider (RHIC). The strong damping of heavy-flavor motion through the medium is reflected in a substantial suppression at high pT and a large azimuthal anisotropy v2 of such electrons in Au + Au collisions at RHIC. By requiring a simultaneous description of the nuclear modification factor RAA(pT) and the azimuthal anisotropy v2(pT) in transport models, the viscosity to entropy density ratio of the medium can be estimated as η/s (1.3–2)(1/4π), which is close to the conjectured lower quantum bound and, therefore, near a perfect fluid.
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3. |
- Awes, T., et al.
(author)
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Highlights from PHENIX II
- 2008
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35
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Journal article (peer-reviewed)abstract
- This contribution highlights recent results from the PHENIX Collaboration at RHIC with emphasis on those obtained through lepton and photon measurements in PHENIX.
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4. |
- Biggar, Robert J., et al.
(author)
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Immunoglobulin subclass levels in patients with non-Hodgkin lymphoma
- 2009
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In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 124:11, s. 2616-20
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Journal article (peer-reviewed)abstract
- Allergy/atopy has been suggested to protect against non-Hodgkin lymphoma (NHL) and specific IgE levels are decreased in patients with NHL. We speculated that all immunoglobulin subclass levels might be downregulated in NHL and examined levels of IgM, IgD, IgA, IgE, IgG and IgG(4) in 200 NHL patients and 200 age- and sex-matched controls. Patients with B-cell NHL of many types had consistently lower median immunoglobulin subclass levels than controls. In every subclass except IgD, about 10-15% of B-cell NHL patients had absolute levels below the 2.5 percentile of controls. Subclass levels correlated with each other and many patients had more than one significantly low level. Levels were lowest for IgG(4) and IgE. Patients with chronic lymphocytic leukemia/small lymphocytic lymphoma had especially low total IgE levels. In other B-cell NHL types, total IgE levels were decreased to a similar extent as other immunoglobulin subclasses. In conclusion, low IgE levels are only part of a more generalized loss of immunoglobulins of all subtypes in a wide variety of B-cell NHL types. Low immunoglobulin levels appear to be a consequence of B-cell NHL presence, and we speculate about molecular mechanisms that could reduce all immunoglobulin subclasses in B-cell NHL.
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5. |
- Christiansen, Peter, et al.
(author)
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The influence of detector effects on TPC performance
- 2009
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In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 609:2-3, s. 149-155
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Journal article (peer-reviewed)abstract
- TPC stand alone simulations based on different energy loss models are compared to previously reported measurements with an ALICE TPC prototype. The performance obtained from simulations is shown to depend significantly on all the included detector effects stressing that energy loss model calculations alone are inadequate for describing the performance. When all effects are included, a good quantitative description of both the specific energy loss and the space point resolution can be obtained from all models. This shows that the TPC description in the official ALICE TPC simulation is in agreement with the measured test beam data. (C) 2009 Elsevier B.V. All rights reserved.
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6. |
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7. |
- Espagnon, B., et al.
(author)
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The ALICE muon spetrometer and related physics
- 2008
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35
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Journal article (peer-reviewed)abstract
- ALICE is the LHC experiment dedicated to the study of heavy-ion collisions at extreme energy density where formation of the quark–gluon plasma is expected. Among the different observables, open heavy flavors and heavy quarkonia states are especially relevant. Indeed they will be copiously produced and they will provide sensitive information on the collision. In this paper, the ALICE muon spectrometer will be described as well as the installation status. A few selected topics concerning the muon physics will be addressed and the related expected performances of the ALICE muon spectrometer will be given.
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8. |
- Franz, A., et al.
(author)
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Highlights from PHENIX I
- 2008
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35
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Journal article (peer-reviewed)abstract
- This contribution highlights recent results from the PHENIX Collaboration at RHIC. It covers global variables, flow and 2-particle correlations. A second contribution in this issue, by T C Awes (2008 J. Phys. G: Nucl. Part. Phys. 35 104007), covers PHENIX results on heavy quarks, leptons and photons.
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9. |
- Homma, K., et al.
(author)
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Systematic studies of global observables in PHENIX
- 2008
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35
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Journal article (peer-reviewed)abstract
- Systematic studies of global observables in different collision systems are indispensable for mapping the QCD phase diagram. Fluctuations in these quantities can provide fundamental information relevant for the phase transitions. The following global observables relevant to critical behavior are studied: the longitudinal density correlation, K to π and p to π fluctuations, and the constituent quark number scaling for elliptic flows.
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10. |
- Hornback, D., et al.
(author)
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Measurements of heavy-quark production via single leptons at PHENIX
- 2008
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35
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Journal article (peer-reviewed)abstract
- The measurement of single leptons from the semi-leptonic decay of heavy-flavor hadrons has long been a means for studying heavy-quark production. PHENIX has measured single muons in pp collisions at forward rapidity and single electrons in both pp and AuAu collisions at mid-rapidity at . The most recent PHENIX single lepton results are presented in the context of state-of-the-art pQCD calculations. An updated azimuthal anisotropy, v2(pT), measurement for heavy-flavor single electrons in AuAu collisions is also presented.
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