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  • Publication . Preprint . Article . Conference object . 2018
    Open Access English
    Authors: 
    Moser, Daniel; Abele, Hartmut; Bosina, Joachim; Fillunger, Harald; Soldner, Torsten; Wang, Xiangzun; Zmeskal, Johann; Konrad, Gertrud;
    Publisher: HAL CCSD
    Country: France
    Project: FWF | Particles and Interaction... (W 1252)

    The beta decay of the free neutron provides several probes to test the Standard Model of particle physics as well as to search for extensions thereof. Hence, multiple experiments investigating the decay have already been performed, are under way or are being prepared. These measure the mean lifetime, angular correlation coefficients or various spectra of the charged decay products (proton and electron). NoMoS, the Neutron decay prOducts MOmentum Spectrometer, presents a novel method of momentum spectroscopy: it utilizes the $R \times B$ drift effect to disperse charged particles dependent on their momentum in an uniformly curved magnetic field. This spectrometer is designed to precisely measure momentum spectra and angular correlation coefficients in free neutron beta decay to test the Standard Model and to search for new physics beyond. With NoMoS, we aim to measure inter alia the electron-antineutrino correlation coefficient $a$ and the Fierz interference term $b$ with an ultimate precision of $\Delta a/a < 0.3\%$ and $\Delta b < 10^{-3}$ respectively. In this paper, we present the measurement principles, discuss measurement uncertainties and systematics, and give a status update. Comment: 7 pages, 4 figures, accepted to the Proceedings of the International Workshop on Particle Physics at Neutron Sources PPNS 2018, Grenoble, France, May 24-26, 2018

  • Publication . Preprint . Article . Conference object . 2012
    Open Access English
    Authors: 
    Roehlly, Y.; Burgarella, D.; Buat, V.; Giovannoli, É.; Noll, S.; Serra, P.;
    Publisher: HAL CCSD
    Country: France

    We present CIGALE (Burgarella et al. 2005; Noll et al. 2009), a software developed at the Laboratoire d'Astrophysique de Marseille to fit galaxy spectral energy distributions from the rest-frame far-UV to far-IR wavelength range, and to derive some of their physical parameters. We also give some examples of scientific results obtained with CIGALE. 4 pages, 2 figures, proceeding of a poster to be presented at ADASS XXI in Paris

  • Closed Access English
    Authors: 
    Bernard Klonjkowski; Dieter Klein; Sandra Galea; Francoise Gavard; Martine Monteil; Lidia Duarte; Annie Fournier; Sophie Sayon; Kamila Górna; Reinhard Ertl; +4 more
    Publisher: HAL CCSD
    Country: France

    International audience; The evaluation of vaccine strategies in animal models is essential for the development of a vaccine against HIV. In efficacy trials conducted in non-human primate models of AIDS, vaccines based on adenoviruses compared favourably with other vaccine vectors. To determine whether this strategy could be transposed to another animal model, and by extension, to humans, we have evaluated the efficacy of adenoviral vectors in a natural model of AIDS, infection of the cat by the feline immunodeficiency virus (FIV). Recombinant canine adenoviruses expressing the envelope glycoproteins or the Gag protein of a primary strain of FIV were constructed. Three groups of six cats were immunised twice with vectors expressing FIV antigens or with a vector expressing an irrelevant antigen, green fluorescent protein, by intramuscular and subcutaneous routes. Humoral responses were elicited against the transgene product in 6/6, 3/6 and 0/6 cats after immunisation against green fluorescent protein, Gag or the envelope glycoproteins, respectively. Six weeks after the second administration, cats were challenged by the intraperitoneal route with the homologous strain, and viral burden in plasma was followed by quantitative RT-PCR. Immunisation with FIV antigens did not afford protection. Rather, viral RNA was detected at earlier time points in cats immunised against Gag than in cats immunised with a vector expressing an irrelevant antigen. Such immune-mediated enhancement did not appear to have a long-range impact on viral set point or inversion of the CD4(+)/CD8(+) ratio. Thus, in the feline AIDS model pre-existing immunity against a viral antigen exacerbated acute phase infection.

  • Publication . Article . Conference object . 2017
    Open Access English
    Authors: 
    Alessandro Chiancone; Florence Forbes; Stéphane Girard;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | PERSYVAL-lab (ANR-11-LABX-0025)

    International audience; Sliced Inverse Regression (SIR) has been extensively used to reduce the dimension of the predictor space before performing regression. SIR is originally a model free method but it has been shown to actually correspond to the maximum likelihood of an inverse regression model with Gaussian errors. This intrinsic Gaussianity of standard SIR may explain its high sensitivity to outliers as observed in a number of studies. To improve robustness, the inverse regression formulation of SIR is therefore extended to non-Gaussian errors with heavy-tailed distributions. Considering Student distributed errors it is shown that the inverse regression remains tractable via an Expectation- Maximization (EM) algorithm. The algorithm is outlined and tested in the presence of outliers, both in simulated and real data, showing improved results in comparison to a number of other existing approaches.

  • Publication . Article . Other literature type . Conference object . 2017
    Open Access English
    Authors: 
    Ruggero Caravita; Stefano Aghion; Claude Amsler; Germano Bonomi; R. S. Brusa; Massimo Caccia; Fabrizio Castelli; Giovanni Cerchiari; Daniel Comparat; Giovanni Consolati; +51 more
    Countries: Italy, Italy, France
    Project: EC | ANGRAM (748826)

    International audience; Positronium (Ps), the unstable bound state of electron and positron, is a valuable system for neutral antimatter spectroscopic studies and for antihydrogen production. Forming a pulsed beam cold antihydrogen using charge-exchange with the Rydberg Ps is the goal of the AEgIS Collaboration, which aims to measure gravity on neutral antimatter. Recent results achieved in producing, manipulating and studying Ps are summarized. Ps has been first produced with mesoporous silica targets in a reflection geometry. Spectroscopy of Ps n = 3 state has been conducted, yielding as a byproduct an independent estimate of the produced Ps temperature. Efficient laser excitation to the Rydberg levels was then achieved, validating the proof-of-concept of AEgIS. Subsequently, production of Ps from a new class of transmission targets was also achieved, opening the possibility for future experiments.

  • Open Access English
    Authors: 
    Thomas Waitz; Hans-Peter Karnthaler; Christian Rentenberger;
    Publisher: HAL CCSD
    Country: France

    The martensitic hcp→dhcp transformation was studied in single crystals of Co-0.85 at.%Fe by transmission electron microscopy (TEM) methods. During in-situ heating dhcp lamellae emerge into the hcp areas of the TEM specimens. The minimum thickness of the lamellae is about 15 close packed planes. Frequently lamellae are observed that grow in thickness by the movement of superledges that are up to about 100 close packed planes in height. The partials at the fronts of the transformation were analysed on an atomic level in TEM images with atomic resolution. The analysis shows that the transformation fronts consists of a sequence of very narrow dipoles compensating their long range strain fields. Since dipoles of a common Burgers vector are observed it is proposed that their short range interactions might promote their correlated nucleation.

  • Publication . Part of book or chapter of book . Conference object . 2015
    Open Access English
    Authors: 
    Verena Fuchsberger; Martin Murer; Manfred Tscheligi; Jose Abdelnour-Nocera; Pedro Campos; Frederica Gonçalves; Barbara Rita Barricelli;
    Publisher: HAL CCSD
    Country: France

    International audience; This one-day workshop aims to contribute to the goals of the IFIP 13.6 Human Work Interaction Design (HWID) working group, i.e., to establish relationships between empirical work-domain studies and recent developments in interaction design. This goal translates to the workshop by focusing on work environments that are challenging for research and design; from physically or spatially unusual workplaces (e.g., oil platforms), mentally demanding or specifically boring work (e.g., control rooms, academics) to challenging social situations at work (e.g., in hospitals). The workshop aims to discuss resulting constraints for research and design, e.g., restricted access for research, or difficulties in articulating the specifics of the workplaces to a wider audience that is not familiar with them. Some work environments may even impede forms of design research, e.g., critical or provocative design will be hard to carry out in safety- or efficiency-critical workplaces. Thus, ways to generate knowledge addressing the design of interactive artifacts for challenging workplaces will be discussed.

  • Publication . Other literature type . Article . Conference object . 2004
    Open Access English
    Authors: 
    Bernard Jouffrey; Peter Schattschneider; Cécile Hébert;
    Publisher: HAL CCSD
    Countries: Switzerland, France

    Abstract We resolve the long-standing mysterious discrepancy between the experimental magic angle in EELS— ∼ 2 ϑ E —and the quantum mechanical prediction of ∼ 4 ϑ E . A relativistic approach surpassing the usually applied kinematic correction yields a magic angle close to the experimental value. The reason is that the relativistic correction of the inelastic scattering cross section in anisotropic systems is significantly higher than in isotropic ones.

  • Publication . Conference object . 2018
    Open Access English
    Authors: 
    Alexey Bakhirkin; Thomas Ferrère; Oded Maler;
    Publisher: HAL CCSD
    Country: France
    Project: EC | STATOR (306595)

    International audience; We describe a new algorithm for the parametric identification problem for signal temporal logic (STL), stated as follows. Given a dense-time real-valued signal w and a parameterized temporal logic formula phi, compute the subset of the parameter space that renders the formula satisfied by the signal. Unlike previous solutions, which were based on search in the parameter space or quantifier elimination , our procedure works recursively on phi and computes the evolution over time of the set of valid parameter assignments. This procedure is similar to that of monitoring or computing the robustness of phi relative to w. Our implementation and experiments demonstrate that this approach can work well in practice.

  • Publication . Other literature type . Article . Conference object . 2018
    Open Access English
    Authors: 
    O. Khalidova; Stefano Aghion; Claude Amsler; M. Antonello; A. S. Belov; Germano Bonomi; R. S. Brusa; Massimo Caccia; A. Camper; Ruggero Caravita; +54 more
    Publisher: HAL CCSD
    Countries: Italy, France
    Project: EC | AVA (721559)

    Abstract AE g ¯ IS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is a CERN based experiment aiming to probe the Weak Equivalence Principle of General Relativity with antimatter by studying free fall of antihydrogen in the Earth’s gravitational field. A pulsed cold beam of antihydrogen produced by charge exchange between Rydberg positronium and cold antiprotons will be horizontally accelerated by an electric field gradient. The free fall of antihydrogen will then be measured by a classical moire deflectometer. An overview of the experimental setup, present status of the experiment along with current achievements and results is presented.

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