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- 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. |
- Ahmed, M., et al.
(författare)
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Search for the lepton-family-number nonconserving decay μ +→e +γ
- 2002
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Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 65:11
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Tidskriftsartikel (refereegranskat)abstract
- The MEGA experiment, which searched for the muon- and electron-number violating decay μ +→e + γ, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the experiment are discussed. The most stringent upper limit on the branching ratio, B(μ + →e + γ)<1.2×10 -11 with 90% confidence, is derived from a likelihood analysis.
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5. |
- Alcorn, J, et al.
(författare)
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Basic instrumentation for Hall A at Jefferson Lab
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 522:3, s. 294-346
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Tidskriftsartikel (refereegranskat)abstract
- The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.
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8. |
- Bernsten, Cecilia, et al.
(författare)
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Improving the well-being of elderly patients via community pharmacy-based provision of pharmaceutical care : a multicentre study in seven European countries
- 2001
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Ingår i: Drugs & Aging. - 1170-229X .- 1179-1969. ; 18:1, s. 63-77
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study aimed to measure the outcomes of a harmonised, structured pharmaceutical care programme provided to elderly patients: (greater than or equal to 65 years of age) by community pharmacists in a multicentre international study performed in 7 European countries. Design and setting: The study was a randomised, controlled. longitudinal, clinical trial with repeated measures performed over an Is-month period. A total of 104 intervention and 86 control pharmacy sites participated in the research and 1290 intervention patients and 1164 control patients were recruited into the study. Main outcome measures and results: A general decline in health-related quality of lift: over time was observed in the pooled data; however, significant improvements were achieved in patients involved in the pharmaceutical care programme in some countries. Intervention patients reported better control of their medical conditions as a result of the study and cost savings associated with pharmaceutical care provision were observed in most countries. The new structured service was well accepted by intervention patients and patient satisfaction with the services improved during the study. The pharmacists involved in providing pharmaceutical care had a positive opinion on the new approach, as did the majority of general practitioners surveyed. The positive effects appear to have been achieved via social and psychosocial aspects of the intervention, such as the increased support provided by community pharmacists, rather than via biomedical mechanisms. Conclusions: This study is the first large-scale, multicentre study to investigate the effects of pharmaceutical care provision by community pharmacists to elderly patients. Future research methodology and implementation will be informed by the experience gained from this challenging trial.
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10. |
- Ivchenko, Nickolay V., et al.
(författare)
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Application of cogwheel phase cycling to sideband manipulation experiments in solid-state NMR
- 2003
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Ingår i: Journal of magnetic resonance. - 1090-7807 .- 1096-0856. ; 164:2, s. 286-293
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Tidskriftsartikel (refereegranskat)abstract
- Cogwheel phase-cycling schemes are applied to sideband suppression and sideband separation experiments in solid-state NMR. It is shown that cogwheel phase cycles lead to the elimination of most pulse imperfection effects, while using far fewer experimental signal acquisitions than conventional phase-cycling methods.
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11. |
- Ivchenko, Nickolay V., et al.
(författare)
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Multiplex phase cycling
- 2003
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Ingår i: Journal of magnetic resonance. - 1090-7807 .- 1096-0856. ; 160:1, s. 52-58
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Tidskriftsartikel (refereegranskat)abstract
- We discuss a new class of phase cycling procedures, in which a set of individual phase-shifted transients are stored separately in the computer and processed afterwards to yield the separated NMR signals from two or more coherence transfer pathways. In the case of two-dimensional double-quantum spectroscopy, this multiplex acquisition procedure allows the acquisition of pure-absorption spectra in only 62.5% of the time needed by previous methods.
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13. |
- López, P.E.M., et al.
(författare)
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Principal Type Specialisation
- 2002
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Ingår i: Proceedings of the ACM SIGPLAN Symposium on Partial Evaluation and Semantics-Based Program Manipulation, Aizu, 12-14 September 2002. - New York, NY, USA : ACM. ; , s. 94-105
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Konferensbidrag (refereegranskat)abstract
- Type specialisation is an approach to program specialisation that works with both a program and its type to produce specialised versions of each. As it combines many powerful features, it appears to be a good framework for automatic program production, - despite the fact that it was designed originally to express optimal specialisation for interpreters written in typed languages. The original specification of type specialisation used a system of rules expressing it as a generalised type system, rather than the usual view of specialisation as generalised evaluation. That system, while powerful, has some weaknesses not widely recognized - the most important being the inability to express principal type specialisations (a principal specialisation is one that is "more general" than any other for a given specialisable term, and from which those can be obtained by a suitable notion of instantiation). This inability is a problem when extending type specialisation to deal with polymorphism or modules. This work presents a different formulation of the system specifying type specialisation capturing the notion of principal specialisation for a language with static constructions and polyvariance. It is a step forward in the study of type specialisation for polymorphic languages and lazy languages, and also permits modularity of specialisation, and better implementations.
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