| 1. |
- Abreu, P., et al.
(författare)
-
Search for sleptons in e+e- collisions at √s = 183 to 189 GeV
- 2001
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 19:1, s. 29-42
-
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.
|
|
| 2. |
- Abreu, P., et al.
(författare)
-
Measurement of the gluon fragmentation function and a comparison of the scaling violation in gluon and quark jets
- 2000
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 13:4, s. 573-589
-
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..
|
|
| 3. |
- Abreu, P., et al.
(författare)
-
Study of dimuon production in photon-photon collisions and measurement of QED photon structure functions at LEP
- 2001
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 19:1, s. 15-28
-
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.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Miguez-Burbano, M. J., et al.
(författare)
-
Continued high risk behaviors in HIV infected drug abusers
- 2002
-
Ingår i: Journal of Addictive Diseases. - 1055-0887 .- 1545-0848. ; 21:4, s. 67-80
-
Tidskriftsartikel (refereegranskat)abstract
- To characterize current risk behaviors of HIV drug abusers in the highly active antiretroviral therapy (HAART) era, socio-demographic, medical and behavioral information were obtained and immune measurements determined. High-risk sexual practices were prevalent. Participants diagnosed before 1995 were 6 times more likely to have unprotected sex with HIV+ partners (p = 0.05) and 11 times more likely to use contaminated needles (p = 0.05) than participants with later diagnosis. Consistent condom use was reported by only 7% of the cohort. Many (43%) of the participants reported multiple HIV+ and HIV- concurrent partners. Most (65%), particularly women (OR = 3, p = 0.02), did so for drugs or money. Despite detectable viral loads, 36% reported unprotected anal sex. Antiretroviral-treated men, compared to non-treated, tended to have unprotected anal sex (OR = 2, p = 0.07). The continued high-risk behaviors of HIV drug users, particularly those diagnosed before 1995 and/or on antiretroviral therapy, indicates an urgent need for new public health strategies.
|
|
| 9. |
- Shor-Posner, G., et al.
(författare)
-
Impact of selenium status on the pathogenesis of mycobacterial disease in HIV-1-infected drug users during the era of highly active antiretroviral therapy
- 2002
-
Ingår i: Journal of Acquired Immune Deficiency Syndromes. - 1525-4135 .- 1944-7884. ; 29:2, s. 169-173
-
Tidskriftsartikel (refereegranskat)abstract
- The risk of mycobacterial disease is significantly increased in drug abusers as well as in immunocompromised HIV-1-infected individuals. The essential trace element selenium has an important function in maintaining immune processes and may, thus, have a critical role in clearance of mycobacteria. The impact of selenium status on the development of mycobacterial diseases in HIV-1-seropositive drug users was investigated over a 2-year period (1999-2001). Twelve cases of mycobacterial disease (tuberculosis, 9; infection due to atypical Mycobacterium species, 3) occurred; these 12 cases were compared with 32 controls with no history of respiratory infections who were matched on age, sex, and HIV status. Significant risk for development of mycobacterial disease was associated with a CD4 cell count of <200/mm(3), malnutrition, and selenium levels of less than or equal to 135 mug/L (patients with these levels were 13 times more likely to develop mycobacterial disease). Multivariate analyses controlling for antiretroviral treatment and CD4 cell count revealed that both body mass index and selenium level remained significant factors in the relative risk for developing mycobacterial disease (relative risk, 3; p =.015); these findings suggest that selenium status may have a profound impact on the pathogenesis of mycobacterial disease.
|
|
| 10. |
- Simancas, J.F., et al.
(författare)
-
The seismic crustal structure of the Ossa-Morena Zone and its geological interpretation
- 2004
-
Ingår i: Journal of Iberian Geology. - 1698-6180 .- 1886-7995. ; 30, s. 133-142
-
Tidskriftsartikel (refereegranskat)abstract
- The IBERSEIS deep reflection seismic experiment has provided a crustal image of the Variscan orogen of southwest Iberia. A brief presentation of the entire seismic profile is given, and then the Ossa-Morena Zone (OMZ) and its boundaries are considered. The crust of the OMZ is shown to be divided into an upper crust, characterized by dominantly NE-dipping reflectivity, and a poorly reflective lower crust. The reflectivity of the upper crust has good correlation with the geological cross-section constructed from surface mapping. In the seismic image, the upper crustal geological structures are seen to merge in the middle crust. Nevertheless, the OMZ middle crust is not a mere detachment level, as it shows very unusual features: it appears as a band of strong reflectivity and irregular thickness (the Iberian Reflective Body, IRB) that we interpret as a great sill-like intrusion of basic rocks. The boundaries of the OMZ are considered sutures of the orogen, and their geometrical features, as deduced from geological mapping and the seismic image, are in accordance with the transpressional character of the Variscan collision recorded in SW Iberia. The present Moho is flat, obliterating the root of the orogen.
|
|
