| 1. |
- Adcox, K, et al.
(författare)
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PHENIX detector overview
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions. A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon. Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities. PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution. The detector consists of a large number of subsystems that are discussed in other papers in this volume. The overall design parameters of the detector are presented. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 2. |
- Adler, SS, et al.
(författare)
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Double helicity asymmetry in inclusive midrapidity pi(0) production for polarized p+p collisions at root s=200 GeV
- 2004
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Ingår i: Physical Review Letters. - 1079-7114. ; 93:20: 202002
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the double longitudinal spin asymmetry in inclusive pi(0) production in polarized proton-proton collisions at roots=200 GeV. The data were taken at the Relativistic Heavy Ion Collider with average beam polarizations of 0.27. The measurements are the first in a program to study the longitudinal spin structure of the proton, using strongly interacting probes, at collider energies. The asymmetry is presented for transverse momenta 1-5 GeV/c at midrapidity, where next-to-leading-order perturbative quantum chromodynamic (NLO pQCD) calculations well describe the unpolarized cross section. The observed asymmetry is small and is compared to a NLO pQCD calculation with a range of polarized gluon distributions.
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| 3. |
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| 4. |
- Bearden, IG, et al.
(författare)
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Particle production in central Pb+Pb collisions at 158A GeV/c
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:4
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Tidskriftsartikel (refereegranskat)abstract
- The NA44 experiment has measured single-particle inclusive spectra for charged pions, kaons, and protons as a function of transverse mass near midrapidity in 158A GeV/c Pb+Pb collisions. From the particle mass dependence of the observed m(T) distributions, we are able to deduce a value of about 120 MeV for the temperature at thermal freeze-out. From the observed ratios of the rapidity densities, we find values of the chemical potentials for light and strange quarks and a chemical freeze-out temperature of approximately 140 MeV.
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| 5. |
- Bearden, IG, et al.
(författare)
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Deuteron and triton production with high energy sulphur and lead beams
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 23:2, s. 237-247
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Tidskriftsartikel (refereegranskat)abstract
- Proton and deuteron production has been observed in S+S and S+Pb collisions at 200 A-GeV and in Pb+Pb reactions at 158 A-GeV at the CERN SPS accelerator. For Pb+Pb triton production was also measured. The p and d spectra as well as the p and t spectra were observed in similar rapidity ranges and over similar ranges of transverse momenta per nucleon, making it possible to interpret the cross sections of the composite particles in terms of coalescence mechanisms. Volumes of homogeneity were extracted and compared to pion-pair HBT interferometry results. Special attention is given to the dependence on transverse mass, centrality and rapidity.
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| 6. |
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| 7. |
- Ivanov, Alexander V., et al.
(författare)
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Binuclear cadmium dithiophosphate crystals: 13C, 31P, and 113Cd CP/MAS NMR studies
- 2003
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Ingår i: Russian journal of coordination chemistry. - 1070-3284 .- 1608-3318. ; 29:5, s. 301-306
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Tidskriftsartikel (refereegranskat)abstract
- 31P NMR signals for the terminal and bridging ligands of the complexes were differentiated. The experimental NMR spectra show 31P-111,113Cd and 113Cd-31 P spin-spin couplings only for the terminal ligands. The chemical shift anisotropy δ and the asymmetry parameter η were calculated for 31P and 113Cd NMR signals. It was found that the 31P chemical shifts for the terminal and bridging dithiophosphato groups differ in anisotropy character.
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| 8. |
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| 9. |
- Ivanov, Alexander V., et al.
(författare)
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Structural organization of nickel(II) and copper(II) O,O'-dialkyl phosphorodithioate complexes as probed by X-ray diffraction, EPR, and CP/MAS 13C and 31P NMR
- 2004
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Ingår i: Russian Journal of Inorganic Chemistry. - 0036-0236 .- 1531-8613. ; 49:3, s. 373-385
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Tidskriftsartikel (refereegranskat)abstract
- The nickel(II) and copper(II) complexes [M{S2P(OR)(2)}(2)] (M = Ni, Cu-63, Cu-65; R = C2H5, C3H7, i-C3H7, C4H9, i-C4H9, s-C4H9, i-C5H11, c-C6H11) with eight symmetric O,O'-dialkyl phosphorodithioates were synthesized, and their structures and spectral properties were studied by EPR and CP/MAS C-13 and P-31 NMR. As determined by EPR, the [CuS4] chromophores in the lattice of nickel(II) complexes have predominantly a square-planar structure. The chromophores in complexes with phosphorodithioate ligands incorporating bulky alkyl substituents have somewhat distorted geometries. NMR shows that the Dtph groups in most nickel(II) complexes are structurally equivalent. An exception is [Ni{S2P(OC3H7)(2)}(2)], which gives rise to two (1 : 1) P-31 NMR signals. For [Ni(S2P(O-i-C4H9)(2))(2)], the alpha and beta modifications were obtained. In the alpha modification, the phosphorodithioate groups are nonequivalent, whereas the P modification has structurally equivalent ligands. The broadening of the P-31 NMR signal of the [Ni{S2P(O-s-C4H9)(2)}(2)] complex is rationalized by the existence of six optical isomers (due to two chiral centers in each of the ligands). For the Dtph groups acting as bidentate terminal ligands in the nickel(II) complexes, the P-31 chemical shift anisotropy delta(aniso) and asymmetry parameter eta were calculated from experimental NMR spectra. Single-crystal X-ray diffraction shows that bis(O,O'-dipropyl phosphorodithioato)nickel(II) exists in the form of two centrosymmetric molecules. In the structure of alpha-bis(O,O'-dipropyl phosphorodithioato)nickel(II), the Dtph ligands in the molecule are nonequivalent. The experimental P-31 NMR signals in the spectra of [Ni{S2P(OC3H7)(2)}(2)] and alpha-[Ni{S2P(O-i-C4H9)(2)}(2)] are assigned to the structural positions of phosphorus atoms in the corresponding molecular structures determined by X-ray diffraction.
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| 10. |
- Kalinkin, Alexander M., et al.
(författare)
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Surface oxidation of synthetic pyrrhotite during wetting-drying treatment
- 2000
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Ingår i: Environmental Engineering Science. - : Mary Ann Liebert Inc. - 1092-8758 .- 1557-9018. ; 17:6, s. 329-335
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Tidskriftsartikel (refereegranskat)abstract
- The surface changes of synthetic hexagonal pyrrhotite Fe[10]S[11] during laboratory wetting-drying treatment at 45°C were investigated using FTIR (DRIFT) spectroscopy, FTIR Raman microscopy, and scanning electron microscopy. α-FeO(OH) (goethite) and elemental sulphur were the main products of the surface pyrrhotite oxidation. The formation of goethite and elemental sulphur was studied on the basis of the corrosion theory and using a potential-pH (Pourbaix) diagram. The appearance of oxidation products on the surface of pyrrhotite grains was detected between 10 and 20 h of treatment. The obtained results can be used for comparison of oxidation processes of synthetic pyrrhotite with that of natural sulphide minerals in dumps.
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