| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
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| 5. |
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| 6. |
- Hansson, B. A. M., et al.
(författare)
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Characterisation of a liquid-xenon jet laser-plasma extreme-ultraviolet source
- 2004
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 75:6, s. 2122-2129
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Tidskriftsartikel (refereegranskat)abstract
- A liquid-xenon-jet laser-plasma source for extreme-ultraviolet (EUV) and soft-x-ray generation has been characterized. Being a source candidate for EUV lithography (EUVL), we especially focus on parameters important for the integration of the source in EUVL systems. The deep-ultraviolet (DUV) out-of-band radiation (=120–400 nm) was quantified, to within a factor of two, using a flying-circus tool together with a transmission-grating spectrograph resulting in a total DUV conversion efficiency (CE) of ~0.33%/2sr. The size and the shape of the xenon plasma was investigated using an in-band-only EUV microscope, based on a spherical Mo/Si multilayer mirror and a charge-coupled device detector. Scalability of the source size from 20–270 µm full width at half maximum was shown. The maximum repetition-rate sustainable by the liquid-xenon-jet target was simulated by a double-pulse experiment indicating feasibility of >17 kHz operation. The xenon-ion energy distribution from the plasma was determined in a time-of-flight experiment with a Faraday-cup detector showing the presence of multi-kilo-electron-volt ions. Sputtering of silicon witness plates exposed to the plasma was observed, while a xenon background of >1 mbar was shown to eliminate the sputtering. It is concluded that the source has potential to meet the requirements of future EUVL systems.
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| 9. |
- Jacobsson, A., et al.
(författare)
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Influence of packaging material and storage temperature on texture, colour, and weight of broccoli.
- 2003
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Ingår i: ISHS Acta Horticulturae. - 0567-7572. ; 600, s. 323-323
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Konferensbidrag (refereegranskat)abstract
- Sophisticated packaging solutions can be used in order to preserve vegetables during storage and transport. Polymeric films with selective barriers matching the respiration of the produce, thereby creating an ideal atmosphere inside the package, are available on the market. Fresh broccoli (Brassica oleracea L. var. italica ‘Monterey’) heads were packed in 4 different commercially available polymeric films, and stored at 4 and 10°C respectively. During storage the weight, colour, chlorophyll content and texture were monitored. The investigated polymer materials were oriented polypropylene (OPP), polyvinyl chloride (PVC) and two types of polyethylene (PE) packagings. The choice of packaging material had an impact on the measured quality parameters of broccoli. Storage in OPP resulted in the longest storage life. Broccoli stored in PVC film deteriorated faster than broccoli packaged in the other materials. It was also observed that the influence of the type of packaging material was more important at the higher temperature. The implications of this work for the packaging and storage of fresh broccoli will be discussed.
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| 10. |
- Jacobsson, A., et al.
(författare)
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The effect of packaging material on the sensory properties of broccoli.
- 2003
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Ingår i: ISHS Acta Horticulturae. - 0567-7572. ; 599, s. 323-323
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Konferensbidrag (refereegranskat)abstract
- Three different commercially available polymeric films were studied to determine their effect on the sensory properties of fresh broccoli (Brassica oleracea L. var. Italica cv. ‘Marathon’). The polymer materials investigated were oriented polypropylene (OPP), polyvinyl chloride (PVC) and one low density polyethylene (LDPE) which contained an ethylene absorber. The fresh broccoli was packaged and stored for one week at 10°C or 3 days at 4°C followed by 4 days at 10°C. The oxygen and carbon dioxide concentrations inside the packages were monitored during storage. After storage the broccoli was evaluated according to sensory analyses, i.e. triangle test and quantitative descriptive analysis, by an analytical panel. The panel judged the broccoli according to smell, taste, texture and appearance. The triangle test showed significant differences between the smell of the broccoli samples, stored in the different packaging materials, when cooked. However, no differences between the raw broccoli, stored in the different packaging materials could be detected. The quantitative descriptive analysis showed that the following attributes; fresh smell and taste, chewing resistance, and crispness, differed significantly between the packaged broccoli when cooked. The appearance was shown to be the sensory property of broccoli most affected by the storage conditions, i.e. packaging material used and storage temperature. The results indicated the importance of the packaging material for maintaining the broccoli quality. However, one packaging material that was able to maintain all the studied sensory properties could not be identified.
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