The Persint visualization program for the ATLAS experiment

The Persint program is designed for the three-dimensional representation of objects and for the interfacing and access to a variety of independent applications, in a fully interactive way. Facilities are provided for the spatial navigation and the definition of the visualization properties, in order to interactively set the viewing and viewed points, and to obtain the desired perspective. In parallel, applications may be launched through the use of dedicated interfaces, such as the interactive reconstruction and display of physics events. Recent developments have focalized on the interfacing to the XML ATLAS General Detector Description AGDD, making it a widely used tool for XML developers. The graphics capabilities of this program were exploited in the context of the ATLAS 2002 Muon Testbeam where it was used as an online event display, integrated in the online software framework and participating in the commissioning and debug of the detector system.Comment: 9 pages, 10 figures, proceedings of CHEP200

On the Value of R=\Gamma_h/\Gamma_l at LEP

We show that the present experimental LEP average R=\Gamma_h/\Gamma_l= 20.795 +- 0.040 is not unambiguous due to the presence of substantial systematic effects which cannot be interpreted within gaussian statistics. We find by Montecarlo simulation that the C.L. of the original LEP sample is only 3.8 \cdot 10^{-4}. We suggest that a reliable extimate of the true R-value is 20.60< R < 20.98 which produces only a very poor determination of the strong coupling constant at the Z mass scale, 0.10< \alpha_s(M_z)< 0.15.Comment: 4 pages, LaTeX; Postscript file, compressed and uuencoded, availabl

A Systematic Study of Power Corrections from World Deep Inelastic Scattering Measurements

By performing an analysis in moment space using high statistics DIS world data, we extract the values of both the QCD parameter $\Lambda^{(4)}_{\bar{MS}}$ up to NLO and of the power corrections to the proton structure function, $F_2$. At variance with previous analyses, the use of moments allows us to extend the kinematical range to larger values of $x$, where we find that power corrections are quantitatively more important. Our results are consistent with the $n$ dependence predicted by IR renormalon calculations. We discuss preliminary results on nuclear targets with the intent of illustrating a possible strategy to disentangle power corrections ascribed to IR renormalons from the ones generated dynamically e.g. from rescattering in the final state. The latter appear to be modified in nuclear targets.Comment: 4 pages, 2 figures, LateX with espcrc2 and epsfi

Evolution of Parton Distributions

I present a highly efficient method for evolving parton distributions in perturbative QCD. The method allows evolving the parton distribution functions according to any of the commonly-used truncations of the evolution equations (which differ in their treatment of higher-order terms). I also give formul\ae\ for computing crossing functions within the method.Comment: 28 pages, TeX, "draft" notice delete

Budgethilfe und die Deklaration von Paris: „Eine Frage des Massstabs“ Fallbeispiel Mali

Der engagierte Beobachter Westafrikas kommt heute nicht umhin, sich mit den Millenniumsentwicklungszielen (MDG), den Strategienrahmen zur Armutsbekämpfung (Poverty Reduction Strategy Papers – PRSP), der Budgethilfe und den „hochrangigen“ Erklärungen, namentlich der Deklaration von Paris über die Wirksamkeit der Hilfe, auseinanderzusetzen. Die folgenden Ausführungen zielen nicht darauf ab, gegen die neuen Vorhaben in der internationalen Entwicklungszusammenarbeit zu polemisieren. Vielmehr soll..

Processes and Dynamics of Global to Regional Ocean Heat Uptake and Variability

Since the 1970s the ocean has absorbed over 90% of the excess heat trapped in the Earth system due to increasing greenhouse gases. However, sparse observations limit our understanding of the processes driving this heat uptake and its regional patterns. In this thesis, three numerical modelling projects demonstrate how ocean warming has played out over the last 50 years, including how it is affected by El Niño-Southern Oscillation (ENSO), the Earth's dominant mode of interannual climate variability. Part 1 of this thesis investigates recent multi-decadal ocean heat content trends basin-by-basin, including what proportion of the total trend is forced by atmospheric surface warming, surface wind changes or both. The analysis reveals that Southern Ocean heat uptake accounts for almost all the planet’s ocean warming since the 1970s, thereby controlling the rate of climate change. This heat uptake is facilitated in almost equal parts by both warming of the atmosphere and changes in the surface winds. An integral part of forecasting ENSO is the analysis of the Pacific warm water volume (WWV), the volume of water above 20°C between 5°S and 5°N of the equator. This is because WWV variations lead ENSO events by 6-8 months. WWV variability is thought to be dominated by adiabatic advection of warm water into and out of the equatorial latitude band. Part 2 uses a complete heat budget to illustrate that WWV changes associated with diabatic processes (surface heat fluxes and vertical mixing) are also important. ENSO impacts remote regions around the globe, including West Antarctica through its atmospheric teleconnections to the Amundsen Sea. Subsurface warming associated with ENSO in this region has the potential to affect basal melting of West Antarctic ice shelves, yet our knowledge of the oceanic ENSO response here remains limited. Part 3 reveals that during El Niño, the Amundsen Sea Low and coastal easterlies in West Antarctica weaken and reduce the poleward Ekman transport of cold waters across the shelf break. Consequently, warm Circumpolar Deep Water (CDW) flows onto the continental shelf to balance this mass deficit. The La Niña shelf circulation response is largely opposite and inhibits cross-shelf upwelling of CDW. This has implications for global sea level rise as basal melting can reduce the buttressing of the ice sheets behind the West Antarctic ice shelves

Limits on the Ununified Standard Model

The ununified standard model is an extension of the standard model that contains separate electroweak gauge groups for quarks and leptons. When it was originally proposed, data allowed the new gauge bosons to be quite light. We use recent data from precision electroweak measurements to put stringent bounds on the ununified standard model. In particular, at the 95% confidence level, we find that the ununified gauge bosons must have masses above about 2 TeV.Comment: 14 pages, plain TeX, 2 postscript figures, figures also available at http://smyrd.bu.edu/htfigs/figure.htm

La coopération suisse au Mali : un positionnement original

La coopération suisse au Mali a concentré son travail sur l’enjeu des déséquilibres entre le centre et les périphéries. En choisissant de renforcer les capacités des collectivités territoriales de trois pôles de développement économique, elle cherche à construire ses appuis progressivement, dans une dé­marche pédagogique d’appui budgétaire aux collectivités décentralisées en cohérence avec le processus de réforme de l’aide et en complémentarité avec la plupart des donateurs qui œuvrent sur la..

Schweizerische Entwicklungszusammenarbeit in Mali: ein origineller Ansatz

Im Mittelpunkt der schweizerischen Entwicklungszusammenarbeit in Mali steht die Reduktion des Ungleichgewichts zwischen Zentrum und Peripherie. Als Schwerpunkt wurde der schrittweise Kapazitätsaufbau der Gebietskörperschaften in drei Wirtschaftspolen gewählt. Gemäss der Neuausrichtung der Entwicklungszusammenarbeit und als Ergänzung zu den Bestrebungen der meisten im Lande engagierten Geber gewährt sie den dezentralisierten Gebietskörperschaften Budgethilfe. Die öffentliche Entwicklungshilfe ..

Soft gluon effects in the extraction of higher twists at large Bjorken x

Existing data on the (unpolarised) transverse structure function of the proton are analyzed for large values of the Bjorken variable x. The leading-twist and a phenomenological higher-twist contributions are simultaneously determined from a power correction analysis of the Nachtmann moments for values of the squared four-momentum transfer between ~ 1 and 20 (GeV/c)**2. The results obtained adopting the next-to-leading order approximation and those including the effects of soft gluon resummation are compared. The sensitivity of the extraction of large-x higher twists to high-order radiative corrections as well as to the value of alphas(MZ) is illustrated.Comment: revised version to appear in Phys. Lett. B: discussion of higher-twist models included; misprints in Eq. (1) and (10) correcte