| 1. |
- Abreu, P., et al.
(författare)
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Search for sleptons in e+e- collisions at √s = 183 to 189 GeV
- 2001
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 19:1, s. 29-42
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Tidskriftsartikel (refereegranskat)abstract
- Data taken by the DELPHI experiment at centre-of-mass energies of 183 GeV and 189 GeV with a total integrated luminosity of 212 pb-1 have been used to search for the supersymmetric partners of the electrons, muons, and taus in the context of the Minimal Supersymmetric Standard Model (MSSM). The decay topologies searched for were the direct decay (ℓ̃ → ℓx̃), producing acoplanar lepton pairs plus missing energy, and the cascade decay (ℓ → ℓx̃0 2 → ℓγx̃0 1), producing acoplanar lepton and photon pairs plus missing energy. The observed number of events is in agreement with Standard Model predictions. The 95% CL excluded mass limits for selectrons, smuons and staus are mẽ ≤ 87 GeV/c2, mμ̃ ≤ 80 GeV/c2 and mτ̃ 75 GeV/c2, respectively, for values of μ=-200 GeV/c2 and tanβ=1.5.
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| 2. |
- Abreu, P., et al.
(författare)
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Measurement of the gluon fragmentation function and a comparison of the scaling violation in gluon and quark jets
- 2000
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 13:4, s. 573-589
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Tidskriftsartikel (refereegranskat)abstract
- The fragmentation functions of quarks and gluons are measured in various three-jet topologies in Z decays from the full data set collected with the DELPHI detector at the Z resonance between 1992 and 995. The results at different values of transverse momentum-like scales are compared. A parameterization of the quark and gluon fragmentation functions at a fixed reference scale is given. The quark and gluon fragmentation functions show the predicted pattern of scaling violations. The scaling violation for quark jets as a function of a transverse momentum-like scale is in a good agreement with that observed in lower energy e+e- annihilation experiments. For gluon jets it appears to be significantly stronger. The scale dependences of the gluon and quark fragmentation functions agree with the prediction of the DGLAP evolution equations from which the colour factor ratio CA/CF is measured to be: CA/CF = 2.26 ± 0.09stat. ± 0.06sys. ± 0.12clus.,scale..
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| 3. |
- Abreu, P., et al.
(författare)
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Study of dimuon production in photon-photon collisions and measurement of QED photon structure functions at LEP
- 2001
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 19:1, s. 15-28
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Tidskriftsartikel (refereegranskat)abstract
- Muon pair production in the process e+e- → e+e- μ+μ- is studied using the data taken at LEP1 (√s ≃ mz) with the DELPHI detector during the years 1992-1995. The corresponding integrated luminosity is 138.5 pb-1. The QED predictions have been tested over the whole Q2 range accessible at LEP1 (from several GeV2/c4 to several hundred GeV2/c4) by comparing experimental distributions with distributions resulting from Monte Carlo simulations using various generators. Selected events are used to extract the leptonic photon structure function Fγ 2. Azimuthal correlations are used to obtain information on additional structure functions, Fγ A and Fγ B, which originate from interference terms of the scattering amplitudes. The measured ratios Fγ A/Fγ 2 and FγB/Fγ 2 are significantly different from zero and consistent with QED predictions.
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| 4. |
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| 5. |
- Menad, Nourreddine, et al.
(författare)
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Study of the presence of fluorine in the recycled fractions during carbothermal treatment of EAF dust
- 2003
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Ingår i: Waste Management. - 0956-053X .- 1879-2456. ; 23:6, s. 483-491
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Tidskriftsartikel (refereegranskat)abstract
- Carbothermal treatment tests of electric arc furnace dusts (EAFD) using the Waelz kiln process were carried out in pilot-scale for the production of zinc oxide. The association of halides in the EAFD, and the recycled products, such as zinc oxide fumes and high-grade iron contents fractions were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. XRD reveals the presence of chlorine and fluorine in the dusts in the form of KCl, NaCl and CaF2. An ultra-pure fraction of zinc was obtained after the Double Leaching Waelz Oxide (DLWO) process was performed on the zinc oxide fumes. The halide contents were reduced to approximately 100 ppm Cl and 700 ppm F. The rest of these elements are in the form of CaF2. About 65% F is volatilised as lead and zinc fluorides, 15% is expected in the magnetic fractions and 20% in non-magnetic fractions as CaF2 and MnF2, respectively.
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| 6. |
- Ruiz, J. A., et al.
(författare)
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Autoionisation of superexcited states in N-2 to the N2+B state
- 2003
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 372:02-jan, s. 139-146
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Tidskriftsartikel (refereegranskat)abstract
- Vibrationally resolved N-2(+) (B-X) (1-2) and (0-1) emission bands were recorded after photoexcitation of N-2 in the 20-46 eV energy range. The branching ratio between these transitions reveals strong non-Franck-Condon effects. Ab initio calculations using a configuration interaction method based on Kohn-Sham orbitals indicate that the autoionisation of certain superexcited states is responsible for some structures present in the branching ratio curve.
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| 7. |
- Ruiz, J. M., et al.
(författare)
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Selective excitation of the np sigma(1)Sigma(+)(u) and np pi(1)Pi(u) to E,F (1)Sigma(+)(g) emission systems in molecular hydrogen using synchrotron radiation
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 388:03-jan, s. 31-35
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Tidskriftsartikel (refereegranskat)abstract
- The npsigma(1)Sigma(u)(+) and nppi(1)Pi(u) states in H-2 have been selectively excited using monoenergetic synchrotron light in the range 14.4-15.5 eV and the subsequent emission was observed using a grating spectrometer. In total 22 well separated bands of the npsigma(1)Sigma(u)(divided by) and nppi(1)Pi(u) to E,F (1)Sigma(g)(divided by) systems (n = 3-7) were observed and rotationally analysed. The intensities of the P and R branches relative to the Q branch vary strongly in the nppi to EF bands confirming the existence of predissociations of a large number of nppi(1)Pi(divided by) levels. Energy levels of the E,F (1) Sigma(g)(divided by) state (v(EF) = 0, 1, 3, 6-10) are obtained which confirm earlier determinations from other H-2 experiments.
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| 8. |
- Stankiewicz, M., et al.
(författare)
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Relaxation dynamics of SF6 studied by energy-resolved electron ion coincidence technique
- 2004
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 137-40, s. 369-375
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Tidskriftsartikel (refereegranskat)abstract
- The mass spectra from the SF6 molecule acquired by energy-resolved electron ion coincidence (EREICO) technique using (1t(1g) + [5t(1u),1t(2u)]), (3e(g) + 1t(2g)), 4t(1u), and 5a(1g) electrons after both valence and S 2p(-1) 6a(1g) core excitation reveal a strong selectivity in the dissociation from these states. From the comparison of the obtained spectra, the influence of the core-excited state in the relaxation pathway of the molecule is studied. The S 2p --> 6a(1g) core excitation does not affect the relaxation dynamics after participator Auger decay to the (1t(1g) + [5t(1u),1t(2u)])(-1) and (4t(1u))(-l) states, but it alters the relaxation dynamics after participator Auger decay to the (3e(g) + 1t(2g))(-1) and (5a(1g))(-1) states with respect to the decay processes after direct excitation of the same orbitals. These observations point to core excitation induced dissociation in the SF6 molecule.
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