University of Grenoble

About: University of Grenoble is a education organization based out in Saint-Martin-d'Hères, France. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 25658 authors who have published 45143 publications receiving 909760 citations.

Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector.

Abstract: Studies of the spin, parity and tensor couplings of the Higgs boson in the [Formula: see text], [Formula: see text] and [Formula: see text] decay processes at the LHC are presented. The investigations are based on [Formula: see text] of pp collision data collected by the ATLAS experiment at [Formula: see text] TeV and [Formula: see text] TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers [Formula: see text], is tested against several alternative spin scenarios, including non-SM spin-0 and spin-2 models with universal and non-universal couplings to fermions and vector bosons. All tested alternative models are excluded in favour of the SM Higgs boson hypothesis at more than 99.9 % confidence level. Using the [Formula: see text] and [Formula: see text] decays, the tensor structure of the interaction between the spin-0 boson and the SM vector bosons is also investigated. The observed distributions of variables sensitive to the non-SM tensor couplings are compatible with the SM predictions and constraints on the non-SM couplings are derived.

Arsenic in shallow, reducing groundwaters in southern Asia : An environmental health disaster

Abstract: Arsenic concentrations in shallow, reducing groundwaters in Bengal, Southeast Asia, and elsewhere constitute a major hazard to the health of people using these waters for drinking, cooking, or irrigation. A comparison of occurrences in the Ganges-Brahmaputra, Mekong, and Red River basins shows that common geological characteristics include (1) river drainage from the rapidly weathering Himalayas, (2) rapidly buried organic-bearing and relatively young (ca. Holocene) sediments, and (3) very low, basin-wide hydraulic gradients. Anaerobic microbial respiration, utilizing either sedimentary or surface-derived organic carbon, is one important process contributing to the mobilization of arsenic from host minerals, notably hydrous iron oxides. In spite of the paucity of data from before the extensive development of groundwater pumping in these areas, there is sufficient evidence to make a prima facie case that human activity might exacerbate arsenic release into these groundwaters. The difficulties in implementing comprehensive groundwater remediation suggest serious attention should be given to developing treatment technologies for alternative surface-water supplies.

Structure of synthetic monoclinic Na-rich birnessite and hexagonal birnessite: II. Results from chemical studies and EXAFS spectroscopy

Abstract: Solution chemical techniques were used to study the conversion of synthetic Na-rich buserite (NaBu) to hexagonal (H 1 -exchanged) birnessite (HBi) at low pH. The low-pH reaction is broadly characterized by the exchange of structural Na 1 with solution H 1 and the partial loss of Mn 21 to the aqueous phase. The desorption of Na 1 in two temporally distinct steps indicates the existence of two types of binding sites for this cation. Mn 21 EXAFS measurements on Na-rich birnessite (NaBi) show that this mineral is primarily a layered structure formed by edge-sharing MnO6 octahedra, with no evidence for triple- corner (TC) sharing Mn. HBi is significantly different with strong evidence for TC-sharing Mn and therefore layer vacancies. The relative numbers of edge (E)-sharing and TC-shar- ing neighbors determined from EXAFS measurements on HBi is consistent with SAED results (Drits et al. 1997), which suggest that the layer vacancies are restricted to every third row of Mn cations, with 50% of the Mn sites along these rows vacant. The density of vacancies in the entire layer is therefore one in six of layer Mn sites. Polarized EXAFS measurements on orientated films of NaBi and HBi confirm the absence of TC-sharing Mn in NaBi and indicate that Mn adsorbed at layer vacancy sites in HBi at pH 4 is dominantly Mn 31 . The intensity of the TC-sharing contribution to the Mn EXAFS spectra of HBi samples increases with increasing pH from pH 2 to 5, and supports a mechanism of formation involving both the direct migration of layer Mn 31 to interlayer TC-sharing positions and re-adsorption of Mn 21 from solution onto layer vacancy sites. The migration of Mn 31 cations into the interlayer releases the steric strain associated with the Jahn-Teller distortion of these octahedra. This model of the NaBu-to-HBi conversion explains the transformation from orthogonal to hexagonal layer symmetry, respectively, as reported by Drits et al. (1997). Analysis of the Zn EXAFS spectrum of Zn 21 -exchanged birnessite shows that Zn 21 also occupies TC-sharing positions at layer vacancy sites. The results of this study strongly suggest that lattice cation vacancies are of critical importance in adsorption and electron transfer processes occurring at the surface of this mineral.

The Gould's Belt Distances Survey (GOBELINS) II. Distances and Structure toward the Orion Molecular Clouds

Abstract: We present the results of the Gould's Belt Distances Survey of young star-forming regions toward the Orion Molecular Cloud Complex. We detected 36 young stellar objects (YSOs) with the Very Large Baseline Array, 27 of which have been observed in at least three epochs over the course of two years. At least half of these YSOs belong to multiple systems. We obtained parallax and proper motions toward these stars to study the structure and kinematics of the Complex. We measured a distance of 388 ± 5 pc toward the Orion Nebula Cluster, 428 ± 10 pc toward the southern portion L1641, 388 ± 10 pc toward NGC 2068, and roughly ~420 pc toward NGC 2024. Finally, we observed a strong degree of plasma radio scattering toward λ Ori.