Measuring the free fall of antihydrogen

After the first production of cold antihydrogen by the ATHENA and ATRAP experiments ten years ago, new second-generation experiments are aimed at measuring the fundamental properties of this anti-atom. The goal of AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is to test the weak equivalence principle by studying the gravitational interaction between matter and antimatter with a pulsed, cold antihydrogen beam. The experiment is currently being assembled at CERN's Antiproton Decelerator. In AEGIS, antihydrogen will be produced by charge exchange of cold antiprotons with positronium excited to a high Rydberg state (n > 20). An antihydrogen beam will be produced by controlled acceleration in an electric-field gradient (Stark acceleration). The deflection of the horizontal beam due to its free fall in the gravitational field of the earth will be measured with a moire deflectometer. Initially, the gravitational acceleration will be determined to a precision of 1%, requiring the detection of about 105 antihydrogen atoms. In this paper, after a general description, the present status of the experiment will be reviewed

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Exploring the WEP with a pulsed cold beam of antihydrogen

The AEGIS experiment, currently being set up at the Antiproton Decelerator at CERN, has the objective of studying the free fall of antimatter in the Earth's gravitational field by means of a pulsed cold atomic beam of antihydrogen atoms. Both duration of free fall and vertical displacement of the horizontally emitted atoms will be measured, allowing a first test of the WEP with antimatter

Recherche d'une quatrieme famille de leptons dans les interactions proton-antiproton a 630 GeV avec le detecteur UA1

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Contribution des voies de la cyclooxygénase et de la NO synthase aux propriétés pharmacologiques des anti-inflammatoires non stéroïdiens

NANCY1-SCD Pharmacie-Odontologie (543952101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

From classical xenon fringes to hydrogen interferometry

International audienceA setup with three equally spaced transmission gratings can be described as a moiré deflectometer in the classical regime and as a Talbot–Lau interferometer in the quantum regime. We successfully operate such a three-grating device with a de Broglie wavelength span of more than two orders of magnitude (20 fm to 2.2 pm), employing different particles such as xenon, krypton, argon, helium, and hydrogen. With that we directly observe the transition from the classical description with fast xenon atoms, to the characteristic quantum behaviour of the Talbot–Lau interferometer using hydrogen atoms with correspondingly long de Broglie wavelength. The systematic study of the interference pattern gives important insights in the feasibility of a proton or antiproton interferometer with this setup

Influence des propriétés physicochimiques d'hydroxyapatites sur le comportement cellulaire. Effect of the physicochemical characteristics of hydroxyapatite on the cell behaviour.

soumis à ITBMLes biocéramiques phosphocalciques sont utilisées comme substitut osseux depuis de nombreuses décennies. Le descellement aseptique après une arthroplastir totale est un problème majeur en chirurgie orthopédique. Les particules d'hydroxyapatite issues du biomatériau ont été identifiées comme cause majeure de l'échec de l'implantation. Pour cette raison et afin d'augmenter la longévité des implants aprés une arthroplastie, des recherches dans le domaine de ces particules relarguées sont donc nécessaires. Dans cet article, nous discutons de la réponse cellulaire (principalement des monocytes/macrophages qui sont parmi les premières cellules à coloniser le site inflammatoire) après exposition à des particules ayant des caractéristiques différentes (taille, forme, température de traitement et composition chimique). Les caractéristiques les plus importantes sont d'abord la forme puis la taille des particules. En effets, les particules sous forme d'aiguille induisent une plus grande production de médiateurs de l'inflammation et elles sont plus toxiques pour les cellules. La température de traitement semble être moins importante même si elle joue un rôle important dans les processus de dissolution/précipitation. Peu de choses sont connues sur l'effet d'ions dopant l'hydroxyapatite (comme le zinc, le strontium,...) sur la réponse cellulaire. Les premières données montrent que le dopage semble bénéfique pour les cellules

Impact des mutations de la tyrosine phosphatase SHP2 dans la réponse à l'hormone de croissance (conséquences physiopathologiques dans le retard de croissance associé au syndrome de Noonan)

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Properties of small cirrus ice crystals from commercial aircraft measurements and implications for flight operations

Measurements of cloud ice crystal size distributions have been made by a backscatter cloud probe (BCP) mounted on five commercial airliners flying international routes that cross five continents. Bulk cloud parameters were also derived from the size distributions. As of 31 December 2014, a total of 4399 flights had accumulated data from 665 hours in more than 19 000 cirrus clouds larger than 5 km in length. The BCP measures the equivalent optical diameter (EOD) of individual crystals in the 5–90 µm range from which size distributions are derived and recorded every 4 seconds. The cirrus cloud property database, an ongoing development stemming from these measurements, registers the total crystal number and mass concentration, effective and median volume diameters and extinction coefficients derived from the size distribution. This information is accompanied by the environmental temperature, pressure, aircraft position, date and time of each sample. The seasonal variations of the cirrus cloud properties measured from 2012 to 2014 are determined for six geographic regions in the tropics and extratropics. Number concentrations range from a few per litre for thin cirrus to several hundreds of thousands for heavy cirrus. Temperatures range from 205 to 250 K and effective radii from 12 to 20 µm. A comparison of the regional and seasonal number and mass size distributions, and the bulk microphysical properties derived from them, demonstrates that cirrus properties cannot be easily parameterised by temperature or by latitude. The seasonal changes in the size distributions from the extratropical Atlantic and Eurasian air routes are distinctly different, showing shifts from mono-modal to bi-modal spectra out of phase with one another. This phase difference may be linked to the timing of deep convection and cold fronts that lead to the cirrus formation. Likewise, the size spectra of cirrus over the tropical Atlantic and Eastern Brazil differ from each other although they were measured in adjoining regions. The cirrus crystals in the maritime continental tropical region over Malaysia form tri-modal spectra that are not found in any of the other regions measured by the IAGOS aircraft so far, a feature that is possibly linked to biomass burning or dust. Frequent measurements of ice crystal concentrations greater than 1×105 L−1, often accompanied by anomalously warm temperature and erratic airspeed readings, suggest that aircraft often experience conditions that affect their sensors. This new instrument, if used operationally, has the potential of providing real-time and valuable information to assist in flight operations as well as providing real-time information for along-track nowcasting