2,306 research outputs found
Central pseudoscalar production in pp scattering and the gluon contribution to the proton spin
Central pseudoscalar production in scattering is suppressed at small
values of , where is defined as the difference between the momenta
transferred from the two protons. Such a behaviour is expected if the
production occurs through the fusion of two vectors. Photon exchange could
provide the dominant contribution at low transferred momenta, but we argue that
an extension of the experiment could probe the gluon contribution to the proton
spin.Comment: 12 pages, 2 figures and 3 tables, uses epsf.sty. Added references and
tables. Minor changes include
Thermal Performance of the Supporting System for the Large Hadron Collider (LHC) Superconducting Magnets
The LHC collider will be composed of approximately 1700 main ring superconducting magnets cooled to 1.9 K in pressurised superfluid helium and supported within their cryostats on low heat in-leak column-type supports. The precise positioning of the heavy magnets and the stringent thermal budgets imposed by the machine cryogenic system, require a sound thermo-mechanical design of the support system. Each support is composed of a main tubular thin-walled structure in glass-fibre reinforced epoxy resin, with its top part interfaced to the magnet at 1.9 K and its bottom part mounted onto the cryostat vacuum vessel at 293 K. In order to reduce the conduction heat in-leak at 1.9 K, each support mounts two heat intercepts at intermediate locations on the column, both actively cooled by cryogenic lines carrying helium gas at 4.5-10 K and 50-65 K. The need to assess the thermal performance of the supports has lead to setting up a dedicated test set-up for precision heat load measurements on prototype supports. This paper presents the thermal design of the support system of the LHC arc magnets. The results of the thermal tests of a prototype support made in industry are illustrated and discussed. A mathematical model has been set up and refined by the comparison with test results, with the scope of extrapolating the observed thermal performance to different geometrical and material parameters. Finally, the calculated estimate of the heat load budgets of the support system and their contribution to the total cryogenic budget for an LHC arc are presented
The GRAAL high resolution BGO calorimeter and its energy calibration and monitoring system
We describe the electromagnetic calorimeter built for the GRAAL apparatus at
the ESRF. Its monitoring system is presented in detail. Results from tests and
the performance obtained during the first GRAAL experiments are given. The
energy calibration accuracy and stability reached is a small fraction of the
intrinsic detector resolution.Comment: 19 pages, 14 figures, submitted to Nuclear Instruments and Method
Phenomenological evidence for the energy dependence of the mixing angle
A phenomenological analysis on various decay processes is performed using an
energy-dependent mixing angle scheme. Special attention is given
to the radiative couplings between lowest-lying vector and pseudoscalar mesons.
The agreement between our predictions and the experimental values is
remarkable. This analysis opens a connection to two-angle fits in the
sector.Comment: 13 pages. Introduction slightly modified. A second Table added.
Conclusions remain unchange
Aspirin Recapitulates Features of Caloric Restriction
G.K. is supported by the Ligue contre le Cancer Comitede Charente-Maritime (equipe labelisee); Agence National de la Recherche (ANR) - Projets blancs; ANR under the frame of E-Rare-2, the ERA-Net for Research on Rare Diseases; Association pour la recherche sur le cancer (ARC); Canceropole Ile-de-France; Chancelerie des universites de Paris (Legs Poix), Fondation pour la Recherche Medicale (FRM); a donation by Elior; the European Commission (ArtForce); the European Research Council (ERC; ERC-2012-AdG-320339-Immunodeath); Fondation Carrefour; Institut National du Cancer (INCa); INSERM (HTE); Institut Universitaire de France; LeDucq Foundation; the LabEx Immuno-Oncology; the RHU Torino Lumiere; the Searave Foundation; the SIRIC Stratified Oncology Cell DNA Repair and Tumor Immune Elimination (SOCRATE); the SIRIC Cancer Research and Personalized Medicine (CARPEM); and the Paris Alliance of Cancer Research Institutes (PACRI). F.M. is grateful to the FWF for grants LIPOTOX, P 29262, P 27893, P 29203, and P24381-B20 and the BMWFW for grants "Unconventional research" and "Flysleep (80.109/0001 -WF/V/3b/2015). G.M. is funded by the Ramon y Cajal Program (RYC-2013-12751) and supported by Spain's Ministerio de Economia y Competitividad (BFU2015-68539) and the BBVA Foundation (SV-15-FBBVA-2). Some nematode strains used in this work were provided by the Caenorhabditis Genetic Center (CGC) at the University of Minnesota, which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440).Pietrocola, F., Castoldi, F., Markaki, M., Lachkar, S., Chen, G., Enot, D.P., Durand, S., Bossut, N., Tong, M., Malik, S.A., Loos, F., Dupont, N., Mariño, G., Abdelkader, N., Madeo, F., Maiuri, M.C., Kroemer, R., Codogno, P., Sadoshima, J., Tavernarakis, N., Kroemer, G
Efeito do dano mecânico na qualidade fisiológica e na capacidade de expansão de sementes de milho pipoca.
Com o objetivo de dar subsidio aos produtores de sementes e/ou graos de milho pipoca, para melhorar a qualidade fisiologica da producao, sementes da cultivar CMS-43 foram submetidas a tres niveis de danificacao mecanica (sem danos, com danos e com danos dobrados), e avaliadas pelos testes de germinacao, vigor (condutividade eletrica) e capacidade de expansao. Os resultados demonstraram que sementes danificadas reduzem significativamente a germinacao, o vigor e a capacidade de expansao das sementes. Concluiu-se que indiferente a finalidade da producao, sementes e/ou graos, a colheita do milho pipoca precisa ser feita com o minimo de danificacao mecanica possivel, para propiciar um produto com maxima qualidade
Two loop results from one loop computations and non perturbative solutions of exact evolution equations
A nonperturbative method is proposed for the approximative solution of the
exact evolution equation which describes the scale dependence of the effective
average action. It consists of a combination of exact evolution equations for
independent couplings with renormalization group improved one loop expressions
of secondary couplings. Our method is illustrated by an example: We compute the
beta-function of the quartic coupling lambda of an O(N) symmetric scalar field
theory to order lambda^3 as well as the anomalous dimension to order lambda^2
using only one loop expressions and find agreement with the two loop
perturbation theory. We also treat the case of very strong coupling and confirm
the existence of a "triviality bound".Comment: 32 pages, HD-THEP-94-3, replaced because: lines too long, blank line
Integrated Safety and Environment Group: Annual Report 2003
This report summarizes the main activities of the Integrated Safety and Environment (IE) Group of the Safety Commission (TIS) during the year 2003, and the results obtained. The different topics in which the group is active are covered: environment, quality management, safety training and major accidents follow-up
Provisioning and Restoration With Sliceability in GMPLS-Based Elastic Optical Networks [Invited]
Possible fabrication techniques and welding specifications for the external cylinder of the CMS coil
The Compact Muon Solenoid (CMS) is one of the experiments, which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.5 m and the free aperture is 6 m in diameter. This is achieved with a 4 layer and 5 module superconducting Al- stabilized coil energized at a nominal current of 20 kA at 4.5 K. In the CMS coil the structural function is ensured, unlike in other existing Al-stabilized thin solenoids, both by the Al-alloy reinforced conductor and the external cylinder. The calculated stress level in the cylinder at operating conditions is particularly severe. In this paper the different possible fabrication techniques are assessed and compared and a possible welding specification for this component is given. (9 refs)
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