3,518 research outputs found

    Higgs and new physics at high energy

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    The observation of a new particle in the search for the Standard Model (SM) Higgs boson at the LHC, reported by the ATLAS and CMS collaborations, is a milestone in the quest to understand electroweak symmetry breaking. The evidence at the level of 5 σ\sigma for a Higgs boson-like particle has been published by both experiments after a preliminary analysis of the data from the LHC Run-I. Precision measurements of the new particle are of critical importance. This document reviews the mass and spin measurement, the couplings scale factor measurements and the limits on new physics derived from these results.Comment: Presented at the 2014 Flavor Physics and CP Violation (FPCP-2014), Marseille, France, May 26-30 2014, 9 pages, 9 figure

    La necessitat del planejament territorial

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    One-loop corrections for WW to HH in Higgs EFT with the electroweak chiral Lagrangian

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    In this work, we present the computation of the one-loop electroweak radiative corrections to the scattering process WW → HH within the context of the Higgs Effective Field Theory (HEFT). We assume that the fermionic interactions are like in the Standard Model, whereas the beyond Standard Model interactions in the bosonic sector are given by the electroweak chiral Lagrangian (EChL). The computation of the one-loop amplitude and the renormalization program is performed in terms of the involved one-particle-irreducible (1PI) functions and using Rζ covariant gauges. The renormalization of 1PI functions at arbitrary external momenta is a more ambitious program than just renormalizing the amplitude with on-shell external legs, and it has the advantage that they can be used in several scattering amplitudes. In fact, we use here some of the 1PI functions already computed in our previous work (devoted to WZ → WZ). We will complement them here with the computation of the new 1PI functions required for WW → HH. From this renormalization procedure, we will also derive the full set of renormalized coefficients of the EChL that are relevant for this scattering process. In the last part, we will present the numerical results for the EChL predictions of the one-loop level cross section, σ(WW → HH)|1-loop, as a function of the center-of-mass energy, showing the relative size of the one-loop radiative corrections with respect to the tree-level prediction in terms of the EChL coefficients. The results of the one-loop corrections to WW → HH for the SM case will be also presented, for comparison with the EChL case, following the same computational method - i.e., by means of the renormalization of 1PI function

    Structure of lithium catena-poly[3,4-dihydroxopentaborate-1:5-[mu]-oxo]

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    LiH2B5O9, M(r) = 207.0, monoclinic, P2(1)/a, a = 13.576 (4), b = 9.077 (4), c = 5.543 (3) angstrom, beta = 91.47 (1)degrees, V = 682.8 (4)) angstrom3, Z = 4, D(x) = 2.013 g cm-3, lambda(Mo Kalpha) = 0.7107 angstrom, mu = 2.06 cm F(000) = 408, T = 293 K, R = 0.049 for 1689 independent observed reflections. The structure contains chains of B5O9H2]- anions linked through shared O atoms. In each anionic unit two B3O3 rings, each incorporating two triangular BO3 units, are connected by a shared tetrahedral BO4 unit. The Li atom has four O-atom neighbours arranged in an approximately tetrahedral configuration. The Li polyhedra connect B-O polyanions to form a two-dimensional network. Further connections are provided by hydrogen bonds

    What is the initiation step of the Grubbs-Hoveyda olefin metathesis catalyst?

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    Density function theory calculations reveal that the Grubbs-Hoveyda olefin metathesis pre-catalyst is activated by the formation of a complex in which the incoming alkene substrate and outgoing alkoxy ligand are both clearly associated with the ruthenium centre. The computed energies for reaction are in good agreement with the experimental values, reported here

    TileCal TDAQ/DCS communication

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    This document describes the communication between the TDAQ and DCS systems of the Hadronic Tile Calorimeter detector of the ATLAS experiment, currently under commissioning phase at CERN. It is a further step on the TDAQ and DCS communication for TileCal operation. The aim of the implementation is to increase the robustness and understanding of the detector from the two systems involved. The basic principle observed is that the two systems operate independently in parallel. Hence, the knowledge of the status of the whole detector from each of the two systems is required for further analysis of the archived data

    Capillary glucose concentration during oral glucose tolerance test for the diagnosis of gestational diabetes

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    Objective: To assess concordance between two point-of-care testing (POCT) devices and the standard laboratory method in screening for gestational diabetes mellitus (GDM) in Huesca. Methods: Pregnant women who met criteria for an oral glucose tolerance test (OGTT) and attended the laboratory between October 2017 and November 2018 were recruited in this prospective observational study. Glucose was measured in venous (laboratory) and capillary blood (Accu-Chek or Contour Next glucometers). GDM was diagnosed attending to NDDG criteria for venous samples or capillary-specific cut-off. Linear regression, Passing–Bablok, Bland–Altman, and the kappa coefficient were used to study concordance between POCT and laboratory method. Results: Data from 109 women were analyzed (57 for Accu-Chek, 52 for Contour Next). Statistical analyses showed good agreement between both POCT and laboratory method. There were no statistical differences in fasting glucose measurements between capillary and venous samples and both POCT devices meet the ISO 15197 standard. Accu-Chek showed good agreement (k=0.629) regarding the laboratory method in classifying GDM, with an acceptable inter-evaluator bias of 3.5% (P<0.001). Conclusion: POCT can be used to obtain fasting values and reduce overall waiting times for patients. Additionally, Accu-Chek can be used to diagnose GDM in remote areas applying specific cut-off values

    Stabilization of Nanoparticles Produced by Hydrogenation of Palladium–N-Heterocyclic Carbene Complexes on the Surface of Graphene and Implications in Catalysis

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    Palladium nanoparticles (NPs) have been obtained by decomposition of well-defined palladium complexes noncovalently anchored onto the surface of reduced graphene oxide. Morphological analysis by microscopy showed the presence of small palladium NPs homogeneously distributed on the support. Characterization by X-ray photoelectron spectroscopy confirmed that palladium NPs contain Pd(2+) and Pd(0) oxidation states and the presence of N-heterocyclic carbene and bromo ligands. The catalytic properties of the NPs with and without the support have been evaluated in the hydrogenation of alkynes. Supported palladium NPs showed increased activity versus the nonsupported ones and could be recycled up to 10 times without the loss of catalytic activity. The composition of the palladium NPs is different for each catalytic cycle indicating a dynamic process and the formation of different catalytic active species. On the contrary, the unsupported palladium NPs showed limited activity caused by decomposition and could not be recycled. The role of the support has been investigated. The results indicate that the support influences the stability of palladium NPs

    Diaqua­bis­(propane-1,3-diamine)­nickel(II) bis­(propane-1,3-diamine)­disulfato­nickelate(II)

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    The ionic NiII title complex, [Ni(C3H10N2)2(H2O)2][Ni(SO4)2(C3H10N2)2], is built up of [Ni(dipr)2(H2O)2]2+ complex cations and [Ni(dipr)2(SO4)2]2− complex anions (dipr is propane-1,3-diamine). Both NiII atoms display a slightly distorted octa­hedral coordination and are located on inversion centers. There are several types of hydrogen-bonding inter­actions, which connect complex cations and anions into a two-dimensional network parallel to (010). Hydrogen bonds formed by the axially coordinated water mol­ecule of the complex cation and one of the O atoms of the sulfate groups of the complex anion (first type) link them into chains along the c axis. These chains are linked to each other through hydrogen bonds formed by an O atom (second type) of the SO4 groups and NH2 groups of the ligand of the complex cations from neighboring chains, forming a two-dimensional hydrogen-bonded net perpendicular to the b axis. The third type of O atoms of the sulfate groups of the complex anion are also linked into chains by a combination of both previously described types of H-atom connections

    Improving Catalyst Activity in Hydrocarbon Functionalization by Remote Pyrene–Graphene Stacking

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    A copper complex bearing an N‐heterocyclic carbene ligand with a pyrene “tail” attached to the backbone has been prepared and supported on reduced graphene oxide (rGO). The free and supported copper materials have been employed as homogeneous and heterogeneous catalysts in the functionalization of hydrocarbons such as n‐hexane, cyclohexane, and benzene through incorporation of the CHCO2Et unit from ethyl diazoacetate. The graphene‐anchored complex displays higher reaction rates and induces higher yields than its soluble counterpart, features that can be rationalized in terms of a decrease in electron density at the metal center due to a remote net electronic flux from the supported copper complex to the graphene surface.The authors would like to thank the financial support of the MINECO (CTQ2017-82893-C2-1-R and CTQ2015-69153-C2-2- R), Junta de Andalucía (P12-FQM-1765) and Universitat Jaume I (UJI-B2018-23). D. V-E thanks the MINECO for a grant (FPU15/03011). The authors thank the ‘Servei Central d’Instrumentació Científica (SCIC)’ of the Universitat Jaume I
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