[en] The Gauss-Bonnet invariant is one of the most promising candidates for a quadratic curvature correction to the Einstein action in expansions of supersymmetric string theory. We study the evaporation of such Schwarzschild-Gauss-Bonnet black holes which could be formed at future colliders if the Planck scale is of order of TeV, as predicted by some modern brane world models. We show that, beyond the dimensionality of space, the corresponding coupling constant could be measured by the LHC. This opens new windows for physics investigation in spite of the possible screening of microphysics due to the event horizon

[en] The loop quantum gravity is the only theory that proposes a quantum description of space-time and therefore of gravitation. This theory predicts that space is not infinitely divisible but that is has a granular structure at the Planck scale (10^-35 m). Another feature of loop quantum gravity is that it gets rid of the Big-Bang singularity: our expanding universe may come from the bouncing of a previous contracting universe, in this theory the Big-Bang is replaced with a big bounce. The loop quantum theory predicts also the huge number of quantum states that accounts for the entropy of large black holes. (A.C.)

[en] Primordial black holes (PBHs) are among the most exciting enigma of modern physics. Recent experimental measurements of cosmic rays with better accuracy, theoretical investigations on the possible formation mechanisms and detailed evaporation processes have revived the interest in such astrophysical objects. This talk aims to use the latest developments in antiproton propagation models together with new data from AMS, BESS and CAPRICE experiments to constrain the local amount of PBH dark matter. Depending on the diffusion halo parameters, we derive an average upper limit of the order of 1.7 10^-33 g/cm³. The anti-deuteron emission is also studied in a coalescence scheme and is proven to be an interesting probe for PBH dark matter. (author)

[en] To search for very high energy gamma rays from cosmic point sources, an imaging telescope sensitive to the Cherenkov light emitted by relativistic charged particles in atmospheric showers will soon be operational at the Themis site (eastern Pyrenees, France). Placed in the focal plane of a large mirror, the camera consists of a fine matrix of 600 photomultipliers equipped with Winston collecting cones. Fast trigger logic based on a majority coincidence was specially developed with special electronic components. The charge is integrated over a very short time, reducing noise contamination in the signal readout. (orig.)

[en] Quantum mechanics in the vicinity of black holes is a fascinating field of theoretical physics. It involves both general relativity and particle physics, opening new eras to establish the principles of unified theories. In this article, we show that quantum bound states with no classical equivalent - as can easily be seen at the dominant monopolar order - should be formed around black holes for massive scalar particles. We qualitatively investigate some important physical consequences, in particular for the Hawking evaporation mechanism and the associated greybody factors. (orig.)

[en] Anti-hydrogen atoms have been produced in the experiments Alpha and Asacusa at the CERN. 38 atoms of anti-hydrogen have been trapped for 0.172 s in the Alpha experiment. This is the first step towards a real study of the properties of anti-matter. 2 experiments have been imagined to test the effect of gravity on anti-matter, first results are not expected before 2015. A new detector AMS will be installed on the ISS (International Space Station) on the last flight of the Endeavour shuttle. AMS will detect particles and anti-particles that go through the universe. The detection of only 1 nucleus of anti-carbon would be the proof of the existence of an anti-world, on the contrary the no-detection of anti-heavy-nuclei will comfort the theory of an asymmetrical universe. In the standard cosmological model, the universe has lost its original symmetry: matter has triumphed over anti-matter. Another cosmological model supposes a symmetrical universe that links anti-matter to negative mass. This model explains that positive mass tends to aggregate while negative mass tends to go away. This model describes a slow expansion of the universe with no need for the existence of dark matter and dark energy. (A.C.)

[en] A proximity focusing Ring Imaging Cherenkov (RICH) detector with a velocity resolution Δβ/β of about 10^-3 for charge one particles will be built for AMS to identify e(e⁺), p-bar(p), and light nuclei. The AMS is a space-bourne particle physics experiment whose purposes is to search for antimatter, dark matter, and to study cosmic-ray astrophysics. An extensive Monte Carlo simulation study has been conducted to investigate possible RICH configurations. Some first results with a cosmic-ray test of a prototype of proximity RICH counter equipped with a solid radiator (NaF or aerogel) and a detector array of 132 photo-multiplier tubes are reported

[en] A prototype of Proximity Focussing Ring Imaging Cherenkov counter has been built and tested with several radiator materials and configurations, including a dual radiator configuration, using separately cosmic-ray particles and ¹²C beam fragmentation products at several energies. Counter prototype and experimental setup are described, and the results of measurements are reported and compared with simulation results. The performances are discussed in the perspective of the final counter design

[en] Gravitinos are expected to be produced in any local supersymmetric model. Using their abundance prediction as a function of the reheating energy scale, we argue that the next generation of cosmic microwave background experiments could exclude supergravity or strongly favor ''thermal-like'' inflation models if B mode polarized radiation were detected. Galactic cosmic-ray production by evaporating primordial black holes is also investigated as a way of constraining the Hubble mass at the end of inflation. Subsequent limits on the gravitino mass and on the related grand unification parameters are derived

[en] A study prototype of a Proximity Focusing Ring Imaging Cherenkov detector (PFRICH) has been developed and built at the ISN Grenoble. The detector has been tested with cosmic-ray particles, ¹²C beams and fragmentation ions at different energies at GSI-Darmstadt