7,017 research outputs found
Search for the Standard Model Higgs boson at LEP
The combined results of the search for the Standard Model Higgs boson from
the four LEP experiments are given. These results are based on the full data
sample collected by ALEPH, DELPHI, L3 and OPAL at centre-of-mass energies up to
209GeV, corresponding to a total integrated luminosity of about 2.5fb-1. A
slight excess of events over the background expectation is found at the 2sigma
level, originating mainly from the ALEPH 4-jet channel. This excess is
compatible with what expected for the production of a SM Higgs boson with a
mass of 115.6GeV/c2. A combined 95% confidence level lower limit of 114.1GeV/c2
on the mass of the Standard Model Higgs boson is derived.Comment: 12 pages, 4 figures, La Thuile 2002 proceeding
Is there new physics in the 1999 ALEPH data ?
The first results on searches performed by ALEPH on the 1999 data sample are
presented here. They are based on an integrated luminosity of about 54 pb
collected at the two centre-of-mass energies of 192 and 196 GeV. Preliminary
results on searches for supersymmetric particles and for the neutral Higgs
bosons are shown.Comment: 3 page
Beam-Material Interaction
Th is paper is motivated by the growing importance of better understanding of
the phenomena and consequences of high- intensity energetic particle beam
interactions with accelerator, generic target , and detector components. It
reviews the principal physical processes of fast-particle interactions with
matter, effects in materials under irradiation, materials response, related to
component lifetime and performance, simulation techniques, and methods of
mitigating the impact of radiation on the components and envir onment in
challenging current and future applicationComment: 28 pages, contribution to the 2014 Joint International Accelerator
School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14
Nov 201
ATTRIBUTES, COMPLIANCE AND EFFECTIVENESS OF NESTED REGIMESTHE BIOLOGICAL WEAPONS REGIME COMPLEX
Are non-proliferation regimes effective? If so, under which circumstances? Existing theoretical and empirical studies fall short of providing consistent indications of the constraining power of security institutions and non-proliferation regimes on state decisions.
On the one hand, proponents of regimes highlight the overall capacity of institutions to contain the number of proliferators. On the other hand, detractors maintain that regimes have little or no effect on state decision to pursue specific weapons. The empirical associations between framework conventions and the non-proliferation of the weapons under provision have proved unsatisfactory and weak.
Moving from a broader idea of regimes and a graduated notion of effectiveness, this project develops a theoretical argument about the importance of networks of individual institutions (regime complexes) in regime analysis. I argue that regime-complex level data can enhance our capacity to explain actual regime effectiveness, as well as the link between specific institutional features and non-proliferation outcomes.
The project does so, interalia, by introducing a new dataset, which gathers information on several institutions that are part of the biological non-proliferation regime complex. The work then illustrates the use of the new dataset by developing measures of state exposure to the regime-complex in terms of overall embeddedness and compliance
Hadronic interactions of primary cosmic rays with the FLUKA code
The measured fluxes of secondary particles produced by the interactions of
cosmic rays with the astronomical environment represent a powerful tool to
infer some properties of primary cosmic rays. In this work we investigate the
production of secondary particles in inelastic hadronic interactions between
several cosmic rays species of projectiles and different target nuclei of the
interstellar medium. The yields of secondary particles have been calculated
with the FLUKA simulation package, that provides with very good accuracy the
energy distributions of secondary products in a large energy range. An
application to the propagation and production of secondaries in the Galaxy is
presented.Comment: 8 pages, 4 figures; Contribution to the 34th International Cosmic Ray
Conference, July 30 to August 6, The Hague, Netherlands; fixing a typo in the
y-axis label of Fig.
An exploratory study on internet addiction, somatic symptoms and emotional and behavioral functioning in school-aged adolescents
Objective: In the last two decades there has been a significant transformation regarding the use of new technologies. Despite growing acknowledgement concerning the different activities and functions of digital technologies, there remains a lack of understanding on how technology overuse may negatively impact both physical and psychosocial well-being. Although researchers have begun to explore the meaning and implications of excessive Internet use in non-clinical populations of children and adolescents, there is still little consistent knowledge on the topic. This study aimed to extend existing knowledge on the excessive use of the Internet among school-aged adolescents, focusing on its association with recurrent somatic symptoms, depressive risk and behavioral and emotional problems. Method: Two hundred and forty adolescents (51.9% females) aged between 10 and 15, participated in this study. Data was collected using the Childrenâs Somatization Inventory, the Internet Addiction Test, the Childrenâs Depression Inventory, the Youth Self Report and the Emotion Regulation Questionnaire. Structural Equation Model analysis was used to analyse the data. Results: Approximately 21.8% of participants reported excessive Internet use based on Youngâs criteria. Higher levels of Internet use were associated with somatic and depressive symptoms as well as emotional and behavioral problems. Depressive Symptoms predicted both Internet Addiction (b = 0.304, p < 0.001) and Internalizing (b = 0.542, p <0.001) and Externalizing problems (b = 0.484, p < 0.001). Internet Addiction also significantly predicted both Internalizing (b = 0.162, p = 0.02) and Externalizing problems (b = 0.183, p = 0.02). Finally, Structural Equation Modeling showed that the indirect effect of Depressive Symptoms (via Internet Addiction) on Internalizing or Externalizing problems were significant. Conclusions: Longitudinal studies are needed to confirm these findings and to identify the mechanisms linking Internet use, somatic symptoms and adaptive functioning
Distribution of inorganic and organic nutrients in the South Pacific Ocean â evidence for long-term accumulation of organic matter in nitrogen-depleted waters
International audienceThe BIOSOPE cruise of the RV Atalante was devoted to study the biogeochemical properties in the South Pacific between the Marquesas Islands (141° Wâ8° S) and the Chilean upwelling (73° Wâ34° S). The 8000 km cruise had the opportunity to encounter different trophic situations, and especially strong oligotrophic conditions in the Central South Pacific Gyre (SPG, between 123° W and 101° W). In this isolated region, nitrate was undetectable between surface and 160â180 m, while regenerated nitrogen (nitrite and ammonium) only revealed some traces (-1), even in the subsurface maximum. Integrated nitrate over the photic layer, which reached 165 m, was close to zero. In spite of this severe nitrogen-depletion, phosphate was always present at significant concentrations (Ë0.1 ”moles l-1), while silicate maintained at low but classical oceanic levels (Ë1 ”moles l-1). In contrast, the Marquesas region (MAR) at west and Chilean upwelling (UPW) at east were characterized by large nutrient contents one hundred to one thousand fold higher than in the SPG. Distribution of surface chlorophyll concentration reflected this gradient of nitrate availability. The lowest value (0.023 nmoles l-1) was measured in the centre of the SPG, where integrated chlorophyll over the photic layer was very weak (Ë10 mg m-2), since a great part (up to 50%) of the deep chlorophyll maximum (DCM) was located below the 1% light. But, because of the relative high concentration encountered in the DCM (0.2 ”g l-1), chlorophyll a content over the photic layer varied much less (by a factor 2 to 5) than the nitrate content. In contrast to chlorophyll a, integrated content of particulate organic matter (POM) remained more or less constant along the investigated area (500 mmoles m-2, 60 mmoles m-2 and 3.5 mmoles m-2 for particulate organic carbon, particulate organic nitrogen and particulate organic phosphorus, respectively), except in the upwelling where values were two fold higher. Extensive comparison has shown that glass fiber GF/F filters efficiency collected particulate chlorophyll, while a significant fraction of POM (up to 50%) passed trough this filter and was retained by 0.2 ”m Teflon membrane. The most striking feature was the large accumulation of dissolved organic matter (DOM) in the SPG relative to surrounding waters, especially dissolved organic carbon (DOC) where concentrations were at levels rarely measured in oceanic waters (>100 ”moles l-1). Due to this large pool of DOM over the whole photic layer of the SPG, integrated values followed an opposite geographical pattern than this of inorganic nutrients with a large accumulation within the centre of the SPG. While suspended particulate matter in the mixed layer had C/N ratio largely conform to Redfield stoichiometry (C/NË6.6), marked deviations were observed in this excess DOM (C/NË16 to 23). The existence of C-rich dissolved organic matter is recognized as a feature typical of oligotrophic waters, requiring the over consumption of carbon. Thus, in spite of strong nitrate-depletion leading to low chlorophyll biomass, the closed ecosystem of the SPG can produce a large amount of carbon. The implications of this finding are discussed, the conclusion being that, due to the lack of seasonal vertical mixing and weak lateral advection, the dissolved organic carbon biologically produced can be accumulated and stored in the photic layer for a very long period
Energy loss in calorimeters using muon spectrometer information at the 2004 ATLAS Combined Test Beam.
In 2004 an ATLAS Combined Test Beam (CTB) was performed in the CERN North area. A complete slice of the barrel detector and of the muon end-cap was tested, with the following goals: pre-commission the final elements and study the combined detector performance. In this note a combined analysis using calorimeter and muon spectrometer information, based on data samples collected during this test, is presented
Energy deposition studies for the High-Luminosity Large Hadron Collider inner triplet magnets
A detailed model of the High Luminosity LHC inner triplet region with new
large-aperture Nb3Sn magnets, field maps, corrector packages, and segmented
tungsten inner absorbers was built and implemented into the FLUKA and MARS15
codes. In the optimized configuration, the peak power density averaged over the
magnet inner cable width is safely below the quench limit. For the integrated
luminosity of 3000 fb-1, the peak dose in the innermost magnet insulator ranges
from 20 to 35 MGy. Dynamic heat loads to the triplet magnet cold mass are
calculated to evaluate the cryogenic capability. In general, FLUKA and MARS
results are in a very good agreement.Comment: 24 p
A generalized notion of consistency with applications to formal argumentation
We propose a generic notion of consistency in an abstract labelling setting, based on two relations: one of intolerance between the labelled elements and one of incompatibility between the labels assigned to them, thus allowing a spectrum of consistency requirements depending on the actual choice of these relations. As a first application to formal argumentation, we show that traditional Dung's semantics can be put in correspondence with different consistency requirements in this context. We consider then the issue of consistency preservation when a labelling is obtained as a synthesis of a set of labellings, as is the case for the traditional notion of argument justification. In this context we provide a general characterization of consistency-preserving synthesis functions and analyze the case of argument justification in this respect
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