Infrastructure for Detector Research and Development towards the International Linear Collider

The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

Spin alignment of leading K∗(892)0K^{*}(892)^{0} mesons in hadronic Z0Z^0 decays

Helicity density matrix elements for inclusive K*(892)^0 mesons from hadronic Z^0 decays have been measured over the full range of K^*0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum x_p values above 0.3, with the matrix element rho_00 rising to 0.66 +/- 0.11 for x_p > 0.7. The values of the real part of the off-diagonal element rho_1-1 are negative at large x_p, with a weighted average value of -0.09 +/- 0.03 for x_p > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the qq(bar) system from the Z^0 decay. All other helicity density matrix elements measured are consistent with zero over the entire x_p range. The K^*0 fragmentation function has also been measured and the total rate determined to be 0.74 +/- 0.02 +/- 0.02 K*(892)^0 mesons per hadronic Z^0 decay.Helicity density matrix elements for inclusive K*(892)^0 mesons from hadronic Z^0 decays have been measured over the full range of K^*0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum x_p values above 0.3, with the matrix element rho_00 rising to 0.66 +/- 0.11 for x_p > 0.7. The values of the real part of the off-diagonal element rho_1-1 are negative at large x_p, with a weighted average value of -0.09 +/- 0.03 for x_p > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the qq(bar) system from the Z^0 decay. All other helicity density matrix elements measured are consistent with zero over the entire x_p range. The K^*0 fragmentation function has also been measured and the total rate determined to be 0.74 +/- 0.02 +/- 0.02 K*(892)^0 mesons per hadronic Z^0 decay.Helicity density matrix elements for inclusive K*(892)^0 mesons from hadronic Z^0 decays have been measured over the full range of K^*0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum x_p values above 0.3, with the matrix element rho_00 rising to 0.66 +/- 0.11 for x_p > 0.7. The values of the real part of the off-diagonal element rho_1-1 are negative at large x_p, with a weighted average value of -0.09 +/- 0.03 for x_p > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the qq(bar) system from the Z^0 decay. All other helicity density matrix elements measured are consistent with zero over the entire x_p range. The K^*0 fragmentation function has also been measured and the total rate determined to be 0.74 +/- 0.02 +/- 0.02 K*(892)^0 mesons per hadronic Z^0 decay.Helicity density matrix elements for inclusive K*(892)^0 mesons from hadronic Z^0 decays have been measured over the full range of K^*0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum x_p values above 0.3, with the matrix element rho_00 rising to 0.66 +/- 0.11 for x_p > 0.7. The values of the real part of the off-diagonal element rho_1-1 are negative at large x_p, with a weighted average value of -0.09 +/- 0.03 for x_p > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the qq(bar) system from the Z^0 decay. All other helicity density matrix elements measured are consistent with zero over the entire x_p range. The K^*0 fragmentation function has also been measured and the total rate determined to be 0.74 +/- 0.02 +/- 0.02 K*(892)^0 mesons per hadronic Z^0 decay.Helicity density matrix elements for inclusive K ∗ (892) 0 mesons from hadronic Z 0 decays have been measured over the full range of K ∗ 0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum x p values above 0.3, with the matrix element ϱ 00 rising to 0.66 ± 0.11 for x p > 0.7. The values of the real part of the off-diagonal element ϱ 1 - 1 are negative at large x p , with a weighted average value of −0.09 ± 0.03 for x p > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the q q system from the Z 0 decay. All other helicity density matrix elements measured are consistent with zero over the entire x p range. The K ∗ 0 fragmentation function has also been measured and the total rate determined to be 0.74 ± 0.02 ± 0.02 K ∗ (892) 0 mesons per hadronic Z 0 decay

A search for neutral Higgs bosons in the MSSM and models with two scalar field doublets

A search is described for the neutral Higgs bosons h^0 and A^0 predicted by models with two scalar field doublets and, in particular, the Minimal Supersymmetric Standard Model (MSSM). The search in the Z^0 h^0 and h^0 A^0 production channels is based on data corresponding to an integrated luminosity of 25 pb^{-1} from e^+e^- collisions at centre-of-mass energies between 130 and 172GeV collected with the OPAL detector at LEP. The observation of a number of candidates consistent with Standard Model background expectations is used in combination with earlier results from data collected at the Z^0 resonance to set limits on m_h and m_A in general models with two scalar field doublets and in the MSSM. For example, in the MSSM, for tan(beta) > 1, minimal and maximal scalar top quark mixing and soft SUSY-breaking masses of 1 TeV, the 95% confidence level limits m_h > 59.0 GeV and m_A > 59.5 GeV are obtained. For the first time, the MSSM parameter space is explored in a detailed scan.A search is described for the neutral Higgs bosons h^0 and A^0 predicted by models with two scalar field doublets and, in particular, the Minimal Supersymmetric Standard Model (MSSM). The search in the Z^0 h^0 and h^0 A^0 production channels is based on data corresponding to an integrated luminosity of 25 pb^{-1} from e^+e^- collisions at centre-of-mass energies between 130 and 172 GeV collected with the OPAL detector at LEP. The observation of a number of candidates consistent with Standard Model background expectations is used in combination with earlier results from data collected at the Z^0 resonance to set limits on m_h and m_A in general models with two scalar field doublets and in the MSSM. For example, in the MSSM, for tan(beta) > 1, minimal and maximal scalar top quark mixing and soft SUSY-breaking masses of 1 TeV, the 95% confidence level limits m_h > 59.0 GeV and m_A > 59.5 GeV are obtained. For the first time, the MSSM parameter space is explored in a detailed scan

Ciclos de carbono y nitrógeno en plantaciones de palma de aceite: claves para la productividad y la sostenibilidad / Carbon and nitrogen cycling in oil palm plantations: the keys to yield and sustainability

[Spanish] El alto rendimiento y la rentabilidad de las inversio nes en palma de aceite dependen de la fijación de carbono producto de la fotosíntesis en las ojas, la cual está limitada por la radiación, la temperatura y la disponibilidad de gua y nutrientes, en particular el nitrógeno. Los ciclos de carbono y nitrógeno también son factores determinantes para la condición del suelo en particular, la materia orgánica, la acidez y la actividad biológica), la salud de los ecosistemas acuáticos y las emisiones de gases de efecto invernadero. Aunque la productividad y los efectos am bientales del cultivo se han estudiado extensamente, es difícil predecir cómo podrían verse afectados por los cambios en el genotipo, en las condiciones ambientales o en las prácticas de manejo, dada la complejidad de las interacciones entre los ciclos de carbono y nitrógeno, y los factores antes mecanísticos, la integración de nuestro conocimiento a modelos mecanicistas predictivos es esencial para avanzar. Dicha integración se ha logrado recientemente para la palma de aceite utilizando el marco APSIM (www.apsim.info), el cual integra modelos de fisiología de cultivos y de ciclos de agua, carbono y nitrógeno. El modelo ha demostrado tener la capacidad de predecir el crecimiento vegetativo y el rendimiento aropiadamente, y de manera consistente en Papúa Nueva Guinea, en donde fue desarrollado. Ahora debe ser ensayado en un mayor rango de entornos. APSIM Oil Palm tiene un potencial considerable como herramienta para predecir el rendimiento y generar eficiencia al explorar escenarios cuya evaluación experimental no es plausible, tales como los efectos probables de una gestión de fertilizantes distinta, los efectos del tipo de clima y suelo en la productividad, la condición del suelo y el entorno. [English] High yields and return on investment in oil palm all depend on the fixation of carbon by photosynthesis in the leaves, which is limited by radiation, temperature and the availability of water and nutrients, especially nitrogen. The carbon and nitrogen cycles are also key determinants of soil condition (particularly soil organic matter, acidity and biological activity), aquatic ecosystem health and greenhouse gas emissions. Although productivity and environmental effects of cultivation are well studied, it is difficult to predict how they might be affected by changes in genotype, environmental conditions or management practices, because of complex interactions between the carbon and nitrogen cycles and these factors. Integrating our knowledge into mechanistic predictive models is essential to move forward. Such integration has recently been achieved for oil palm using the APSIM framework (www.apsim.info), which integrates models of crop physiology and cycling of water, carbon and nitrogen. The model has been shown to predict vegetative growth and yield consistently well in Papua New Guinea, where it was developed. It now needs to be tested in a wider range of environments. APSIM Oil Palm has considerable potential as a tool for predicting yield and for efficiently exploring scenarios that are not feasible to assess experimentally, such as the likely effects of different fertilizer management, climate or soil type on productivity, soil condition and the environment

Soil fertility changes following conversion of grassland to oil palm

Impacts of palm oil industry expansion on biodiversity and greenhouse gas emissions might be mitigated if future plantings replace grassland rather than forest. However, the trajectory of soil fertility following planting of oil palm on grasslands is unknown. We assessed the changes in fertility of sandy volcanic ash soils (0–0.15 m depth) in the first 25 years following conversion of grassland to oil palm in smallholder blocks in Papua New Guinea, using a paired-site approach (nine sites). There were significant decreases in soil pH (from pH 6.1 to 5.7) and exchangeable magnesium (Mg) content following conversion to oil palm but no significant change in soil carbon (C) contents. Analyses to 1.5 m depth at three sites indicated little change in soil properties below 0.5 m. There was considerable variability between sites, despite them being in a similar landscape and having similar profile morphology. Soil Colwell phosphorus (P) and exchangeable potassium (K) contents decreased under oil palm at sites with initially high contents of C, nitrogen, Colwell P and exchangeable cations. We also assessed differences in soil fertility between soil under oil palm (established after clearing forest) and adjacent forest at two sites. At those sites, there was significantly lower soil bulk density, cation exchange capacity and exchangeable calcium, Mg and K under oil palm, but the differences may have been due to less clayey texture at the oil palm sites than the forest sites. Cultivation of oil palm maintained soil structure and fertility in the desirable range, indicating that it is a sustainable endeavour in this environment

Methods to account for tree-scale variability in soil- and plant-related parameters in oil palm plantations

Background and aims: Lateral tree-scale variability in plantations should be taken into account when scaling up from point samples, but appropriate methods for sampling and calculation have not been defined. Our aim was to define and evaluate such methods. Methods: We evaluated several existing and new methods, using data for throughfall, root biomass and soil respiration in mature oil palm plantations with equilateral triangular spacing. Results: Three ways of accounting for spatial variation within the repeating tree unit (a hexagon) were deduced. For visible patch patterns, patches can be delineated and sampled separately. For radial patterns, measurements can be made in radial transects or a triangular portion of the tree unit. For any type of pattern, including unknown patterns, a triangular sampling grid is appropriate. In the case studies examined, throughfall was 79% of rainfall, with 95% confidence limits being 62 and 96% of rainfall. Root biomass and soil respiration, measured on a 35-point grid, varied by an order of magnitude. In zones with steep gradients in parameters, sampling density has a large influence on calculated mean values. Conclusions: The methods defined here provide a basis for representative sampling and calculation procedures in studies requiring scaling up from point sampling, but more efficient methods are needed