6,431 research outputs found

    Discovery potential for Higgs bosons beyond the SM

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    The discovery potential of the CMS detector for the MSSM neutral and charged Higgs bosons at the LHC is presented based on studies with full detector simulation and event reconstruction of the principal discovery channels.Comment: Prepared for International Europhysics Conference on High Energy Physics (EPS-HEP2007), Manchester, England, 19-25 Jul 200

    Heavy MSSM Higgs Bosons at CMS: "LHC wedge" and Higgs-Mass Precision

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    The search for MSSM Higgs bosons will be an important goal at the LHC. In order to analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons, we combine the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The experimental analyses are done assuming an integrated luminosity of 30 or 60 fb^-1. The results are interpreted as 5 \si discovery contours in MSSM M_A-tan_beta benchmark scenarios. Special emphasis is put on the variation of the Higgs mixing parameter mu. While the variation of mu can shift the prospective discovery reach (and correspondingly the ``LHC wedge'' region) by about Delta tan_beta= 10, the discovery reach is rather stable with respect to the impact of other supersymmetric parameters. Within the discovery region we analyze the accuracy with which the masses of the heavy neutral Higgs bosons can be determined. An accuracy of 1-4% should be achievable, depending on M_A and tan_beta.Comment: Talk given by G.W. at EPS07 (Manchester, July 2007) and talk given by S.H. at SUSY07 (Karlsruhe, July 2007). 4 pages, 2 figure

    Determining the CP parity of Higgs bosons at the LHC in their tau decay channels

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    If neutral Higgs bosons will be discovered at the CERN Large Hadron Collider (LHC) then an important subsequent issue will be the investigation of their CP nature. Higgs boson decays into tau lepton pairs are particularly suited in this respect. Analyzing the three charged pion decay modes of the tau leptons and taking expected measurement uncertainties at the LHC into account, we show that the CP properties of a Higgs boson can be pinned down with appropriately chosen observables, provided that sufficiently large event numbers will eventually be available.Comment: Latex, 10 pages, 4 figure

    Displacement power spectrum measurement of a macroscopic optomechanical system at thermal equilibrium

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    The mirror relative motion of a suspended Fabry-Perot cavity is studied in the frequency range 3-10 Hz. The experimental measurements presented in this paper, have been performed at the Low Frequency Facility, a high finesse optical cavity 1 cm long suspended to a mechanical seismic isolation system identical to that one used in the VIRGO experiment. The measured relative displacement power spectrum is compatible with a system at thermal equilibrium within its environmental. In the frequency region above 3 Hz, where seismic noise contamination is negligible, the measurement distribution is stationary and Gaussian, as expected for a system at thermal equilibrium. Through a simple mechanical model it is shown that: applying the fluctuation dissipation theorem the measured power spectrum is reproduced below 90 Hz and noise induced by external sources are below the measurement.Comment: 11 pages, 9 figures, 2 tables, to be submitte

    Intravascular Ultrasound in the Detection of Bridging Stent Graft Instability During Fenestrated and Branched Endovascular Aneurysm Repair Procedures: A Multicentre Study on 274 Target Vessels

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    Objective: The use of intravascular ultrasound (IVUS) reduces contrast medium use and radiation exposure during conventional endovascular aneurysm repair (EVAR). The aim of this study was to evaluate the safety and efficacy of IVUS in detecting bridging stent graft (bSG) instability during fenestrated and branched EVAR (F/B-EVAR). Methods: This was a prospective observational multicentre study. The following outcomes were evaluated: (1) technical success of the IVUS in each bSG, (2) IVUS findings compared with intra-operative angiography, (3) incidence of post-operative computed tomography angiography (CTA) findings not detected with IVUS, and (4) absence of IVUS related adverse events. Target visceral vessel (TVV) instability was defined as any branch or fenestration issues requiring an additional manoeuvre or re-intervention. Any IVUS assessment that detected stenosis, kinking, or any geometric TVV issue was considered to be branch instability. All procedures were performed in ad hoc hybrid rooms. Results: Eighty patients (69% males; median age 72 years; interquartile range 59, 77 years) from four aortic centres treated with F/B-EVAR between January 2019 and September 2021 were included: 70 BEVAR (21 off the shelf; 49 custom made), eight FEVAR (custom made), and two F/B-EVAR (custom made), for a total of 300 potential TVVs. Two TVVs (0.7%) were left unstented and excluded from the analysis. The TVVs could not be accessed with the IVUS catheter in seven cases (2.3%). Furthermore, 17 (5.7%) TVVs could not be examined due to a malfunction of the IVUS catheter. The technical success of the IVUS assessment was 91.9% (274/298), with no IVUS related adverse events. Seven TVVs (2.5%) showed signs of bSG instability by means of IVUS, leading to immediate revisions. The first post-operative CTA at least 30 days after the index procedure was available in 268 of the 274 TVVs originally assessed by IVUS. In seven of the 268 TVVs (2.6%) a re-intervention became necessary due to bSG instability. Conclusion: This study suggests that IVUS is a safe and potentially valuable adjunctive imaging technology for intra-operative detection of TVV instability. Further long term investigations on larger cohorts are required to validate these promising results and to compare IVUS with alternative technologies in terms of efficiency, radiation exposure, procedure time, and costs

    Inertial control of the mirror suspensions of the VIRGO interferometer for gravitational wave detection

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    In order to achieve full detection sensitivity at low frequencies, the mirrors of interferometric gravitational wave detectors must be isolated from seismic noise. The VIRGO vibration isolator, called 'superattenuator', is fully effective at frequencies above 4 Hz. Nevertheless, the residual motion of the mirror at the mechanical resonant frequencies of the system are too large for the interferometer locking system and must be damped. A multidimensional feedback system, using inertial sensors and digital processing, has been designed for this purpose. An experimental procedure for determining the feedback control of the system has been defined. In this paper a full description of the system is given and experimental results are presented.Comment: 17 pages, 11 figures, accepted for publication on Review of Scientific Instrument

    Protective green cover enhances soil respiration and native mycorrhizal potential compared with soil tillage in a high-density olive orchard in a long term study

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    Arbuscular mycorrhizal fungi (AMF), living in symbiosis with most food crops, improve plant growth and nutrition and provide fundamental ecosystem services. Here, the possibility of increasing root density and native AMF activity through appropriate soil management practices was investigated, comparing the long-term (10 years) effects of a permanent green cover (GC) with shallow tillage (ST) in a high-density olive orchard in a Mediterranean environment. Olive root density, AMF colonization, and soil mycorrhizal inoculum potential (MIP) were determined after trench excavations at different soil depths. Soil respiration was determined by infra-red gas analysis. The activity of native AMF, as assessed by MIP bioassay, was higher in GC plots than in ST ones. Olive roots were well colonized by AMF in both management systems. Soil respiration rates of GC plots were often higher than those of ST, whereas soil moisture and temperature in the topsoil were similar in both treatments. Soil depth significantly affected root density, which peaked at 0.2 m soil depth in both soil treatments. The maintenance of a permanent plant cover appears to be a better option than shallow tillage as a soil management practice to preserve biological soil fertility in olive orchards

    The Floodplain Woods of Tuscany

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    The contraction of lowland forests throughout Europe began in remote times and then intensified strongly with land reclamation by agriculture and urbanization during the first half of the last century. We present a map of the Floodplain Woods of Tuscany on a scale of 1:300,000 as a synthesis of that built at the scale of 1:10,000 and the methods used to obtain it. Nearly 90% of the patches contain habitats of concern to conservation, according to the Habitat Directive. The Tuscan Floodplain Woods remained prevalent in coastal areas, where some levels of protection are guaranteed by the presence of several protected areas, whereas they have practically vanished in the other parts of the regional territory. The resulting patches are very small and distant from each other, so only in-depth management of all potential floodplain forest areas, taking into consideration patches for their regeneration, can be useful to assure their conservation

    Global and regional IUCN red list assessments: 4

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    In this contribution, the conservation status assessments of three vascular plants are presented following to IUCN categories and criteria. It includes the assessment at global level of Saxifraga caprariae Mannocci, Ferretti, Mazzoncini & Viciani and S. montis-christi Mannocci, Ferretti, Mazzoncini & Viciani and the regional assessment of Halocnemum cruciatum (Forssk.) Tod. (Spain)
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