Collisional and Radiative Processes in Optically Thin Plasmas

Most of our knowledge of the physical processes in distant plasmas is obtained through measurement of the radiation they produce. Here we provide an overview of the main collisional and radiative processes and examples of diagnostics relevant to the microphysical processes in the plasma. Many analyses assume a time-steady plasma with ion populations in equilibrium with the local temperature and Maxwellian distributions of particle velocities, but these assumptions are easily violated in many cases. We consider these departures from equilibrium and possible diagnostics in detail

ANTARES: the first undersea neutrino telescope

The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given

Search for a light Higgs resonance in radiative decays of the (1S) with a charm tag

A search is presented for the decay (1S)→γA0, A0→cc¯, where A0 is a candidate for the CP-odd Higgs boson of the next-to-minimal supersymmetric standard model. The search is based on data collected with the BABAR detector at the (2S) resonance. A sample of (1S) mesons is selected via the decay (2S)→π+π-(1S). The A0→cc¯ decay is identified through the reconstruction of hadronic D0, D+, and D∗(2010)+ meson decays. No significant signal is observed. The measured 90% confidence-level upper limits on the product branching fraction B((1S)→γA0)×B(A0→cc¯) range from 7.4×10-5 to 2.4×10-3 for A0 masses from 4.00 to 8.95GeV/c2 and 9.10 to 9.25GeV/c2, where the region between 8.95 and 9.10GeV/c2 is excluded because of background from (2S)→γχbJ(1P), χbJ(1P)→γ(1S) decays

Angular distributions in the decay B -> K*l(+)l(-)

We use a sample of 384 million BBbar events collected with the Babar detector at the PEP-II e+e- collider to study angular distributions in the rare decays B -> K* l+l-, where l+l- is either e+e- or mu+mu-. For low dilepton invariant masses, m(l+l-)3.2$ GeV/c^2, we measure AFB=0.76 (+0.52,-0.32) +/- 0.07 FL=0.71 (+0.20,-0.22) +/- 0.04.We are grateful for the excellent luminosity and machine conditions provided by our PEP-II colleagues, and for the substantial dedicated effort from the computing organizations that support BABAR. The collaborating institutions wish to thank SLAC for its support and kind hospitality. This work is supported by DOE and NSF (USA), NSERC (Canada), CEA and CNRS-IN2P3 (France), BMBF and DFG (Germany), INFN (Italy), FOM (The Netherlands), NFR (Norway), MES (Russia), MEC (Spain), and STFC (United Kingdom). Individuals have received support from the Marie Curie EIF (European Union) and the A. P. Sloan Foundation.Peer reviewe

The LHCb upgrade I

The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

Reply to comment by Y. Rolland et al. on ''Alpine thermal and structural evolution of the highest external crystalline massif: The Mont Blanc''

International audience1. Introduction[1] Leloup et al. [2005] discussed the Cenozoic structural evolution of the Mont Blanc and Aiguilles Rouges ranges by combining new structural, 0Ar/39Ar, and fission track data with published P-T estimates and geochronological data. Our main conclusions were (1) Alpine exhumation of the Aiguilles Rouges was limited to the thickness of the overlying nappes (10 km), while rocks now outcropping in the Mont Blanc have been xhumed 15 to 20 km.(2) Uplift of the two massifs started 22 Myr ago; while at 12 Ma, the Mont Blanc shear zone (MBsz), a reverse fault with a slight right-lateral component, initiated bringing the Mont Blanc above the Chamonix synclinorium and the Aiguilles Rouges; total vertical throw on the MBsz isbetween 4 and 8 km. (3) Fission track data suggest that relative motion between the Aiguilles Rouges and the Mont Blanc stopped 4 Myr ago. Since that time, uplift of the Mont Blanc has mostly taken place along the Mont Blanc back thrust, a steep north dipping fault zone bounding thesouthern flank of the range. (4) The highest summits are located where the back thrust intersects the MBsz. (5) Exhumation of the Mont Blanc and Aiguilles Rouges occurred toward the end of motion on the Helvetic basal de´collement (HBD) at the base of the Helvetic nappes. Uplift is linked with a deeper, more external thrust that induced the formation of the Jura arc. [2] While acknowledging that our paper is ‘‘a good step forward in the tectonic comprehension of the Mont Blanc area and provides a good synthesis of preexisting data,’’Rolland et al. [2007] claim that the timing we propose for the thrust and back thrust events is not in agreement with new 40Ar/39Ar data that they publish in their comment. In fact, they raise two main arguments with our observations/ interpretations:[3] 1. Alpine deformation is penetrative within the Mont blanc granite and is not accommodated by the two localized shear zones we describe (the SE dipping Mont Blanc shear zone, or MBsz, in the north and the NW dipping back thrust in the south, Figure 1), but by numerous anastomosed shearzones in the way described by Choukroune and Gapais [1983] in the Aar massif and Gourlay [1986] in the Mont Blanc. All deformations within the Mont Blanc are thus coeval and the Mont Blanc is a transpressive pop-up structure at the rim of a large transpressive fault that runs from the Rhone dextral fault system. [4] 2. The timing of deformation cannot be obtained through 40Ar/39Ar thermochronology due to excess argon and intense fluid circulation. They instead provide a minimum age of 16 Ma for the initiation of top to the SE motions on the SE side of the Mont Blanc (back thrust) based on five phengites 40Ar/39Ar ages from three shear zones (their Figure 3). [5] We will take the opportunity of this reply to address these two points and, in a third point, we briefly discuss possible deformation models of the Mont Blanc range

Vitamin D supplementation improves bone mineralisation independent of dietary phosphate in male X-linked hypophosphatemic (Hyp) mice

The disorder of X-linked hypophosphatemia (XLH), results in the supressed renal production of active 1α,25-dihydroxyvitamin D (1,25(OH)2D) due to elevated fibroblast growth factor-23 (FGF23) levels. While adequate 25(OH)D levels are generally associated with improved mineralisation of the skeleton independent of circulating 1,25(OH)2D levels, it is unclear whether raising 25(OH)D to sufficiently high levels through dietary vitamin D₃ administration contributes to improving bone mineralisation in the murine homolog for XLH, Hyp mice. Three-week-old male Hyp mice were fed one of four diets containing either 1000 IU (C) or 20,000 IU (D) vitamin D₃/kg diet with either 0.35% phosphate or 1.25% phosphate (P) until 12 weeks of age (n = 12/group). When compared to C-fed mice, D-fed mice significantly elevated serum 25(OH)D levels to 72.8 ± 4.9 nmol/L (2-fold, p < 0.001) and increased both cortical bone mineral density (15%, p < 0.01), and vertebral trabecular BV/TV% (80%, p < 0.001), despite persistent hypophosphatemia and normocalcemia. The increase in bone volume was associated with improved Tb.Th (12%, p < 0.01) and Tb.N (63%, p < 0.001). Unlike with D-diet, P-fed mice resulted in increased femoral (15%, p < 0.001) and vertebral (12%, p < 0.001) length, and a 34% increase in vertebral trabecular BV/TV% when compared to control fed animals (p < 0.001). However, the addition of the high P diet to the high D diet did not result in additive effects on bone mineralisation when compared to the effects of D diet alone, despite serum 25(OH)D levels elevated to 118.8 ± 8.6 nmol/L. In D-fed mice, the increase in bone mineral density and volume was associated with reduced osteoid volume, reduced ObS/BS, and a trend for reduced serum PTH levels, suggesting reduced bone turnover in these animals. Thus, elevating serum 25(OH)D levels independently improves bone mineralisation in Hyp mice without causing hypercalcemia, suggesting that further studies are required in XLH patients to establish the role of increasing 25(OH)D levels in improving bone mineralisation.Kate R. Barratt, Rebecca K. Sawyer, Gerald J. Atkins, Rene St-Arnaud, Paul H. Anderso

Synkinematic magmatism, heterogeneous deformation, and progressive strain localization in a strike-slip shear zone: The case of the right-lateral Karakorum fault

International audienceNew structural observations coupled with 15 U/Pb and 24 Ar/Ar new ages from the Karakorum shear zone (KSZ) constrain the timing and slip rate of the right-lateral Karakorum fault zone (KFZ), one of the great continental Asian strike-slip faults. In the Tangtse-Darbuk area, the Tangtse (SW) and Muglib (NE) mylonitic strands of the KSZ frame the less deformed Pangong Range. Inherited U/Pb ages show that granitic protoliths are mostly from the Karakorum and Ladakh batoliths, with a major Miocene melting event lasting from ≥21.5 to 13.5 Ma. Some of the Miocene granitic bodies show structural evidence for intrusion synkinematic to the KSZ. The oldest of these granitoids is 18.8 ± 0.4 Ma old, implying that deformation started prior to ∼19 Ma. Microstructural data show that right-lateral deformation pursued during cooling. Ar/Ar data show that ductile deformation stopped earlier in the Tangtse (∼11 Ma) than in the Muglib strand (∼7 Ma). Deformation ended at ∼11 Ma in the Tangtse strand while it is still active in the Muglib strand, suggesting a progressive localization of deformation. When merged with published observations along the KFZ, these data suggest that the KFZ nucleated in the North Ayilari range at least ∼22 Ma ago. The long-term fault rate is 0.84 to 1.3 cm/yr, considering a total offset of 200 to 240 km. The KSZ collected magma produced within the shear zone and/or deeper in crust for which the producing mechanism stays unclear but was not the lower crustal channel flow