Beyond Standard Model searches with top quark at ATLAS

At the LHC, the top quark is expected to be a huge and clean signal. With about eight millions of expected top pairs and three millions of single top events produced per year in the low luminosity runs, and with a low level of backgrounds, the LHC will open a new opportunity for precision measurements of the top quark properties and for exotic topology searches involving top quarks. As the ATLAS discovery potential on new physics with top quark is being assessed with many analyses, this article focuses on two particular topics: heavy neutral resonances and charged Higgs boson searches with top quarks. The analyses and the ATLAS expectations are described

Mid-infrared sub-wavelength grating mirror design: tolerance and influence of technological constraints

High polarization selective Si/SiO2 mid-infrared sub-wavelength grating mirrors with large bandwidth adapted to VCSEL integration are compared. These mirrors have been automatically designed for operation at \lambda = 2.3 $\mu$m by an optimization algorithm which maximizes a specially defined quality factor. Several technological constraints in relation with the grating manufacturing process have been imposed within the optimization algorithm and their impact on the optical properties of the mirror have been evaluated. Furthermore, through the tolerance computation of the different dimensions of the structure, the robustness with respect to fabrication errors has been tested. Finally, it appears that the increase of the optical performances of the mirror imposes a less tolerant design with severer technological constraints resulting in a more stringent control of the manufacturing process.Comment: The final publication is available at http://iopscience.iop.org/2040-8986/13/12/125502

Waiting time distributions in Quantum spin hall based heterostructures

For the distinction of the Andreev bound states and Majorana bound states, we study the waiting time distributions (WTDs) for heterostructures, based on one dimensional edge states of a two dimensional topological insulators (TI) in combination with an proximitized s-wave superconductor (SC) and an applied magnetic field. We show for the time reversal symmetric (TRS) situation of a Josephson junction details of the WTD. This includes different transport processes, different numbers of Andreev bound states and the phase difference of the SC. We further consider a Zeeman field in the normal part of the junctions revealing novel features in the WTD along the phase transition between trivial bound states and Majorana bound states. We finally discuss clear signatures to discriminate between them.Comment: 10 pages, 6 figure

On the accuracy of the ALI method for solving the radiative transfer equation

We solve the integral equation describing the propagation of light in an isothermal plane-parallel atmosphere of optical thickness $\tau^*$, adopting a uniform thermalization parameter $\epsilon$. The solution given by the ALI method, widely used in the field of stellar atmospheres modelling, is compared to the exact solution. Graphs are given that illustrate the accuracy of the ALI solution as a function of the parameters $\epsilon$, $\tau^*$ and optical depth variable $\tau$.Comment: 7 pages, 11 figures, A&A, accepted 30 July 2003, minor correction

Étude des désexcitations électromagnétiques des niveaux 1- situés à 12,44 et 13,09 MeV dans le noyau 16O

Les désexcitations γ des niveaux 1- situés à 12,44 et 13,09 MeV dans le noyau 16O ont été étudiées et deux nouvelles transitions mises en évidence. En outre au cours de ce travail les paramètres des deux niveaux 1- ont été redéterminés

Bilan hydrologique d'un marais littoral à vocation agricole : Le marais de Moëze (Charente-Maritime, France)

En France, les sécheresses consécutives des années 1985, 1986, 1989 et 1990 ont mis en lumière les problèmes relatifs à l'alimentation en eau potable, l'irrigation des terres agricoles et la préservation des écosystèmes aquatiques. Dans le cas des zones humides, continentales et littorales, caractérisées par une compartimentation hydraulique souvent complexe, le manque de connaissance se fait particulièrement sentir. Bien que de nombreux travaux aient permis d'évaluer l'évaporation des masses d'eau et l'évapotranspiration de certaines espèces d'hydrophytes et d'hélophytes, les études débouchant sur des bilans quantitatifs restent peu fréquentes. Le bilan hydrologique du marais de Moëze (2250 ha) a été calculé par décade entre le 11/06/89 et le 31/08/89. Il prend en compte le débit au droit de l'ouvrage d'alimentation, les volumes prélevés pour l'irrigation hors marais, les infiltrations et l'évapotransplration sur les 318 km de canaux. L'estimation de la consommation d'eau des parcelles est globalisée au niveau des mesures d'infiltration.Les pertes par infiltration sont secondaires (9,4 %) au regard des volumes prélevés pour l'irrigation (38,0 %) et évapotransplrés par les canaux (43,7 %) dont 51,1 % uniquement par les 28,6 % des plans d'eau colonisés par Typha latifolia.L'optimisation de la gestion estivale de l'eau d'un marais littoral agricole nécessite dans un premier temps de minimiser les pertes. C'est essentiellement sur la consommation d'eau des canaux colonisés par les hélophytes que l'on peut intervenir. Nous proposons un abaque qui permet d'évaluer l'importance des économies d'eau réalisées en fonction de plusieurs scénarios d'aménagement du réseau hydraulique.In France, the drought that occurred during the years 1985, 1986, 1989 and 1990 have emphazised the problems of freshwater supplies for human consumption, for irrigation and for the conservation of aquatic systems. Today the water has to be economized through a rationalized management. Water balance must be evaluated in order to compare supply an demand. Hydrological functioning is particularly badly known as far as continental and coastal wetlands are concerned, probably because of a generally very complex hydrological partition. Many papers deal with the evaporation rate from a clear water surface or the evapotranspiration rate from several species of hydrophytes and halophytes. However studies of quantitative water budgets of wetlands remain few in number.This paper reports an analysis of the budget summer water in that was a salt marsh now containing freshwater. The 25 km2 marsh of Moëze is located on the French Atlantic coast; it has been progressively constituted by filling up a tidal bay since the flandrien period. The soils correspond to fluvio-marine silts, locally called « bri » accumulated over several tens of meters thick. The marsh is bounded on the North by the ancient limestone coast, on the South by the Arnoult River, and on the West by the coastline. Its drainage network includes permanently flowing main canals and also small silted-up ditches which sometimes dry up in summer and are largely colonized by aquatic plants, particularly Typha latifolia. The channels network is very dense (144 meters of ditches per hectare) and complex because of a close connection between all the canals and ditches. The regional oceanic climate is characterized by a surplus water balance from October to April (+ 315 mm) and quite a short one tram May to September (-338 mm).The important terms of the water budget equation in this study were : the quantity of water pumped from the Arnoult River through the inflow sluicegate (Qa), the precipitations (P), the irrigation out of the marsh (lr), the evapotranspiration of water bodies (Epo), the seepage through canals and ditches (ls), and the change in water soil strorage (Vs). These terms are not equally susceptible to be measured. Groundwater seepage and evapotranspiration are difficult to measure and they are often determined by difference, but, they contain the residual error of ail the terms. The methods to evaluate each term of water budget were carried as follows :1. As the inflow gate functions as a siphon, the flow rate (Qa) was calculated with the drowned orifice formula (LENCASTRE, 1984). The upstream and downstream water levels were permanently recorded by 2 limnigraphs. The upstream and downstream water velocities were measured every 2 days with a micro-currentmeter.2. The precipitation values (P) used in the water budget equation correspond to the average of 4 rain gauges placed around the marsh.3. The evapotranspiration of the channel network (Epo) was directly estimated through 4 experimental floating tanks (0.50 x 0.55 x 1.05 m size) previously used by GIRAUD (1985). One of the tanks was placed in clear water, the others was planted the typical aquatic vegetation of the marsh (Lemna sp., Ceratophyllum sp., and Typhia latifolia). The drop the water levels in the tanks corresponded to the loss of water due tou evapotranspiration. All the tanks were filled up to a fixed level, and the amount of water added, measured every 2 days.4. The outputs for irrigation (Ir) concern 298 ha of maïze out of the marsh, and 23 farmers. The water amounts taken off were estimated form an inquiry of irrigation practices associated to a field control.5. The water losses by seepage (ls) through canals and ditches were directly measured on the field by using the closed basin method. A length of canal was closed by 2 watertight bulkheads. The fall of water level was recorded and the amount of water added to maintain a fixed level was measured. This method is considered by KRAATZ (1977) as being the most accurate specially for low seepage. The fall of water level never exceeds 10 % of the water depth in the basin. 34 canals and ditches in the marsh were sampled. According to CHEVALLIER et al. (1984), 3 parameters influencing the soil permeability were measured : granulometry, CaC03 content and sodicity. After the sampling plan we have retained 4 experimental canals (average length =47 m, average water surface = 135 m2, average depth = 0.44 m).6. The water strorage in the soil (Vs) was evaluated by analyzing the groundwater table fluctuations and moisture changes.The water budget calculated for 10-day periods depending on the climatology calculations, from 10th June 1989 to 31st August 1989. The water losses due to seepage were secondary (9.4 %) compared to the amounts of water taken off by irrigation (38.0 %) and channel network evapotranspiration (43.7 %). The water consumption of helophytes such as Typhia latifolia was 2 to 3 times higher than the evaporation of a clear surface water body as shown in figure 3. In the marsh of Moëze, 51.1 % of channel evapotranspiration was due to the colonization by Typhia latifolia of the canals and ditches although they represent only 28.6 % of the channel network surface.This study shows that is possible to quantify a water budget for a large scale wetland from field measurements associated to experimental approaches, with a satisfactory accuracy : less than 10 %. To reduce the water consumption of the marsh of Moëze, three essential recommendations may be given : the reduction of the global channel network surface, the cleaning of a part of ditches colonized by Typhia latifolia, or the combination of both techniques. According to the different management schemes, it is possible to predict the amounts of freshwater saved (fig. 5)

What's in a voice? Prosody as a test case for the Theory of Mind account of autism

The human voice conveys a variety of information about people's feelings, emotions and mental states. Some of this information relies on sophisticated Theory of Mind (ToM) skills, whilst others are simpler and do not require ToM. This variety provides an interesting test case for the ToM account of autism, which would predict greater impairment as ToM requirements increase. In this paper, we draw on psychological and pragmatic theories to classify vocal cues according to the amount of mindreading required to identify them. Children with a high functioning Autism Spectrum Disorder and matched controls were tested in three experiments where the speakers' state had to be extracted from their vocalizations. Although our results confirm that people with autism have subtle difficulties dealing with vocal cues, they show a pattern of performance that is inconsistent with the view that atypical recognition of vocal cues is caused by impaired ToM

Bilan hydrologique d'un marais littoral à vocation agricole : Le marais de Moëze (Charente-Maritime, France)

En France, les sécheresses consécutives des années 1985, 1986, 1989 et 1990 ont mis en lumière les problèmes relatifs à l'alimentation en eau potable, l'irrigation des terres agricoles et la préservation des écosystèmes aquatiques. Dans le cas des zones humides, continentales et littorales, caractérisées par une compartimentation hydraulique souvent complexe, le manque de connaissance se fait particulièrement sentir. Bien que de nombreux travaux aient permis d'évaluer l'évaporation des masses d'eau et l'évapotranspiration de certaines espèces d'hydrophytes et d'hélophytes, les études débouchant sur des bilans quantitatifs restent peu fréquentes. Le bilan hydrologique du marais de Moëze (2250 ha) a été calculé par décade entre le 11/06/89 et le 31/08/89. Il prend en compte le débit au droit de l'ouvrage d'alimentation, les volumes prélevés pour l'irrigation hors marais, les infiltrations et l'évapotransplration sur les 318 km de canaux. L'estimation de la consommation d'eau des parcelles est globalisée au niveau des mesures d'infiltration.Les pertes par infiltration sont secondaires (9,4 %) au regard des volumes prélevés pour l'irrigation (38,0 %) et évapotransplrés par les canaux (43,7 %) dont 51,1 % uniquement par les 28,6 % des plans d'eau colonisés par Typha latifolia.L'optimisation de la gestion estivale de l'eau d'un marais littoral agricole nécessite dans un premier temps de minimiser les pertes. C'est essentiellement sur la consommation d'eau des canaux colonisés par les hélophytes que l'on peut intervenir. Nous proposons un abaque qui permet d'évaluer l'importance des économies d'eau réalisées en fonction de plusieurs scénarios d'aménagement du réseau hydraulique.In France, the drought that occurred during the years 1985, 1986, 1989 and 1990 have emphazised the problems of freshwater supplies for human consumption, for irrigation and for the conservation of aquatic systems. Today the water has to be economized through a rationalized management. Water balance must be evaluated in order to compare supply an demand. Hydrological functioning is particularly badly known as far as continental and coastal wetlands are concerned, probably because of a generally very complex hydrological partition. Many papers deal with the evaporation rate from a clear water surface or the evapotranspiration rate from several species of hydrophytes and halophytes. However studies of quantitative water budgets of wetlands remain few in number.This paper reports an analysis of the budget summer water in that was a salt marsh now containing freshwater. The 25 km2 marsh of Moëze is located on the French Atlantic coast; it has been progressively constituted by filling up a tidal bay since the flandrien period. The soils correspond to fluvio-marine silts, locally called « bri » accumulated over several tens of meters thick. The marsh is bounded on the North by the ancient limestone coast, on the South by the Arnoult River, and on the West by the coastline. Its drainage network includes permanently flowing main canals and also small silted-up ditches which sometimes dry up in summer and are largely colonized by aquatic plants, particularly Typha latifolia. The channels network is very dense (144 meters of ditches per hectare) and complex because of a close connection between all the canals and ditches. The regional oceanic climate is characterized by a surplus water balance from October to April (+ 315 mm) and quite a short one tram May to September (-338 mm).The important terms of the water budget equation in this study were : the quantity of water pumped from the Arnoult River through the inflow sluicegate (Qa), the precipitations (P), the irrigation out of the marsh (lr), the evapotranspiration of water bodies (Epo), the seepage through canals and ditches (ls), and the change in water soil strorage (Vs). These terms are not equally susceptible to be measured. Groundwater seepage and evapotranspiration are difficult to measure and they are often determined by difference, but, they contain the residual error of ail the terms. The methods to evaluate each term of water budget were carried as follows :1. As the inflow gate functions as a siphon, the flow rate (Qa) was calculated with the drowned orifice formula (LENCASTRE, 1984). The upstream and downstream water levels were permanently recorded by 2 limnigraphs. The upstream and downstream water velocities were measured every 2 days with a micro-currentmeter.2. The precipitation values (P) used in the water budget equation correspond to the average of 4 rain gauges placed around the marsh.3. The evapotranspiration of the channel network (Epo) was directly estimated through 4 experimental floating tanks (0.50 x 0.55 x 1.05 m size) previously used by GIRAUD (1985). One of the tanks was placed in clear water, the others was planted the typical aquatic vegetation of the marsh (Lemna sp., Ceratophyllum sp., and Typhia latifolia). The drop the water levels in the tanks corresponded to the loss of water due tou evapotranspiration. All the tanks were filled up to a fixed level, and the amount of water added, measured every 2 days.4. The outputs for irrigation (Ir) concern 298 ha of maïze out of the marsh, and 23 farmers. The water amounts taken off were estimated form an inquiry of irrigation practices associated to a field control.5. The water losses by seepage (ls) through canals and ditches were directly measured on the field by using the closed basin method. A length of canal was closed by 2 watertight bulkheads. The fall of water level was recorded and the amount of water added to maintain a fixed level was measured. This method is considered by KRAATZ (1977) as being the most accurate specially for low seepage. The fall of water level never exceeds 10 % of the water depth in the basin. 34 canals and ditches in the marsh were sampled. According to CHEVALLIER et al. (1984), 3 parameters influencing the soil permeability were measured : granulometry, CaC03 content and sodicity. After the sampling plan we have retained 4 experimental canals (average length =47 m, average water surface = 135 m2, average depth = 0.44 m).6. The water strorage in the soil (Vs) was evaluated by analyzing the groundwater table fluctuations and moisture changes.The water budget calculated for 10-day periods depending on the climatology calculations, from 10th June 1989 to 31st August 1989. The water losses due to seepage were secondary (9.4 %) compared to the amounts of water taken off by irrigation (38.0 %) and channel network evapotranspiration (43.7 %). The water consumption of helophytes such as Typhia latifolia was 2 to 3 times higher than the evaporation of a clear surface water body as shown in figure 3. In the marsh of Moëze, 51.1 % of channel evapotranspiration was due to the colonization by Typhia latifolia of the canals and ditches although they represent only 28.6 % of the channel network surface.This study shows that is possible to quantify a water budget for a large scale wetland from field measurements associated to experimental approaches, with a satisfactory accuracy : less than 10 %. To reduce the water consumption of the marsh of Moëze, three essential recommendations may be given : the reduction of the global channel network surface, the cleaning of a part of ditches colonized by Typhia latifolia, or the combination of both techniques. According to the different management schemes, it is possible to predict the amounts of freshwater saved (fig. 5)

Energy and CO2 fluxes in temperate deciduous broadleaf forests: using local add-covariance data for a global optimization of ORCHIDEE model

Non peer reviewedPublisher PD