340 research outputs found

    Direct detection of neutralino dark matter in supergravity

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    The direct detection of neutralino dark matter is analysed in general supergravity scenarios, where non-universal soft scalar and gaugino masses can be present. In particular, the theoretical predictions for the neutralino-nucleon cross section are studied and compared with the sensitivity of dark matter detectors. We take into account the most recent astrophysical and experimental constraints on the parameter space, including the current limit on B(Bs-> mu+ mu-). The latter puts severe limitations on the dark matter scattering cross section, ruling out most of the regions that would be within the reach of present experiments. We show how this constraint can be softened with the help of appropriate choices of non-universal parameters which increase the Higgsino composition of the lightest neutralino and minimise the chargino contribution to the b->s transition.Comment: 27 pages, 22 figure

    Decreased plasma nociceptin/orphanin FQ levels after acute coronary syndromes

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    Foregoing researches made on the N/OFQ system brought up a possible role for this system in cardiovascular regulation. In this study we examined how N/OFQ levels of the blood plasma changed in acute cardiovascular diseases. Three cardiac patient groups were created: enzyme positive acute coronary syndrome (EPACS, n = 10), enzyme negative ACS (ENACS, n = 7) and ischemic heart disease (IHD, n = 11). We compared the patients to healthy control subjects (n = 31). We found significantly lower N/OFQ levels in the EPACS [6.86 (6.21–7.38) pg/ml], ENACS [6.97 (6.87–7.01) pg/ml and IHD groups [7.58 (7.23–8.20) pg/ml] compared to the control group [8.86 (7.27–9.83) pg/ml]. A significant correlation was detected between N/OFQ and white blood cell count (WBC), platelet count (PLT), creatine kinase (CK), glutamate oxaloacetate transaminase (GOT) and cholesterol levels in the EPACS group.Decreased plasma N/OFQ is closely associated with the presence of acute cardiovascular disease, and the severity of symptoms has a significant negative correlation with the N/OFQ levels. We believe that the rate of N/OFQ depression is in association with the level of ischemic stress and the following inflammatory response. Further investigations are needed to clarify the relevance and elucidate the exact effects of the ischemic stress on the N/OFQ system

    Origins of the Ambient Solar Wind: Implications for Space Weather

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    The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

    Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

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    An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic epep scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

    Analysis of the modes of energy consumption of the complex of an incoherent scattering of the institute of ionosphere of national academy of sciences and the ministry of education and science of Ukraine

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    ĐŁ ĐŽĐ°ĐœŃ–Đč статті прДЎстаĐČĐ»Đ”ĐœŃ– Ń€Đ”Đ·ŃƒĐ»ŃŒŃ‚Đ°Ń‚Đž Đ°ĐœĐ°Đ»Ń–Đ·Ńƒ Ń€Đ”Đ¶ĐžĐŒŃ–ĐČ Đ”ĐœĐ”Ń€ĐłĐŸŃĐżĐŸĐ¶ĐžĐČĐ°ĐœĐœŃ ĐșĐŸĐŒĐżĐ»Đ”Đșсу ĐœĐ”ĐșĐŸĐłĐ”Ń€Đ”ĐœŃ‚ĐœĐŸĐłĐŸ Ń€ĐŸĐ·ŃŃ–ŃĐœĐœŃ Đ†ĐœŃŃ‚ĐžŃ‚ŃƒŃ‚Ńƒ Ń–ĐŸĐœĐŸŃŃ„Đ”Ń€Đž НАН і МОН ĐŁĐșŃ€Đ°Ń—ĐœĐž Đ· ĐŒĐ”Ń‚ĐŸŃŽ ĐČĐžŃ€Ń–ŃˆĐ”ĐœĐœŃ ĐżŃ€ĐŸĐ±Đ»Đ”ĐŒĐž піЮĐČĐžŃ‰Đ”ĐœĐœŃ Đ”ĐœĐ”Ń€ĐłĐŸĐ”Ń„Đ”ĐșтоĐČĐœĐŸŃŃ‚Ń– ĐœĐ°ŃƒĐșĐŸĐČĐŸ-ĐŽĐŸŃĐ»Ń–ĐŽĐœĐŸĐłĐŸ ĐșĐŸĐŒĐżĐ»Đ”Đșсу та стĐČĐŸŃ€Đ”ĐœĐœŃ Đ”ĐœĐ”Ń€ĐłĐŸĐ”Ń„Đ”ĐșтоĐČĐœĐŸŃ— ŃĐžŃŃ‚Đ”ĐŒĐž ДлДĐșŃ‚Ń€ĐŸĐżĐŸŃŃ‚Đ°Ń‡Đ°ĐœĐœŃ, яĐșĐ° Đ·Đ°Đ±Đ”Đ·ĐżĐ”Ń‡ĐžŃ‚ŃŒ стіĐčĐșу Ń€ĐŸĐ±ĐŸŃ‚Ńƒ ĐœĐ°ŃƒĐșĐŸĐČĐŸĐłĐŸ ĐŸĐ±Đ»Đ°ĐŽĐœĐ°ĐœĐœŃ ĐŽĐ»Ń ĐČĐžĐșĐŸĐœĐ°ĐœĐœŃ ĐŽĐŸŃĐ»Ń–ĐŽĐœĐžŃ†ŃŒĐșох ĐżŃ€ĐŸĐłŃ€Đ°ĐŒ НАН ĐŁĐșŃ€Đ°Ń—ĐœĐž. ĐžĐżĐžŃĐ°ĐœĐ° ŃĐžŃŃ‚Đ”ĐŒĐ° ДлДĐșŃ‚Ń€ĐŸĐ¶ĐžĐČĐ»Đ”ĐœĐœŃ ĐșĐŸĐŒĐżĐ»Đ”Đșсу та Ń€Đ”Đ¶ĐžĐŒĐž Đ”ĐœĐ”Ń€ĐłĐŸŃĐżĐŸĐ¶ĐžĐČĐ°ĐœĐœŃ ĐșĐŸĐŒĐżĐ»Đ”Đșсу. ĐžĐżĐžŃĐ°ĐœĐŸ ĐżŃ€ĐžŃŃ‚Ń€ĐŸŃ— Ń€Đ°ĐŽĐ°Ń€ĐœĐŸŃ— ŃĐžŃŃ‚Đ”ĐŒĐž, Đ° таĐșĐŸĐ¶ ĐœĐ°ĐčĐ±Ń–Đ»ŃŒŃˆ ĐżĐŸŃ‚ŃƒĐ¶ĐœŃ– ŃĐżĐŸĐ¶ĐžĐČачі ДлДĐșŃ‚Ń€ĐŸĐ”ĐœĐ”Ń€ĐłŃ–Ń—, яĐșі ŃĐżĐŸĐ¶ĐžĐČають ДлДĐșŃ‚Ń€ĐŸĐ”ĐœĐ”Ń€ĐłŃ–ŃŽ ĐœĐ° Đ”ĐșŃĐżĐ”Ń€ĐžĐŒĐ”ĐœŃ‚Đ°Đ»ŃŒĐœŃ– і ĐłĐŸŃĐżĐŸĐŽĐ°Ń€ŃŃŒĐșі ĐżĐŸŃ‚Ń€Đ”Đ±Đž. ĐŸŃ€ĐŸĐ°ĐœĐ°Đ»Ń–Đ·ĐŸĐČĐ°ĐœĐŸ Đ”ĐœĐ”Ń€ĐłĐŸŃĐżĐŸĐ¶ĐžĐČĐ°ĐœĐœŃ ĐșĐŸĐŒĐżĐ»Đ”Đșсу ĐœĐ”ĐșĐŸĐłĐ”Ń€Đ”ĐœŃ‚ĐœĐŸĐłĐŸ Ń€ĐŸĐ·ŃŃ–ŃĐœĐœŃ Đ·Đ° 2013 р. ĐžŃ‚Ń€ĐžĐŒĐ°ĐœĐŸ і прДЎстаĐČĐ»Đ”ĐœĐŸ графіĐșĐž ŃĐ”Ń€Đ”ĐŽĐœŃŒĐŸŃ— ŃĐżĐŸĐ¶ĐžĐČĐ°ĐœĐŸŃ— ĐżĐŸŃ‚ŃƒĐ¶ĐœĐŸŃŃ‚Ń– (ŃĐ”Ń€Đ”ĐŽĐœŃŒĐŸĐŽĐŸĐ±ĐŸĐČĐžĐč ĐżĐŸĐșĐ°Đ·ĐœĐžĐș) і ŃĐ”Ń€Đ”ĐŽĐœŃŒĐŸŃ— ŃĐżĐŸĐ¶ĐžĐČĐ°ĐœĐŸŃ— ĐżĐŸŃ‚ŃƒĐ¶ĐœĐŸŃŃ‚Ń– ĐČ Ń€Đ”Đ¶ĐžĐŒŃ– ĐČĐžĐŒŃ–Ń€ŃŽĐČĐ°ĐœŃŒ. ĐžĐżĐžŃĐ°ĐœĐ° ĐŽĐŸŃ†Ń–Đ»ŃŒĐœŃ–ŃŃ‚ŃŒ ĐżŃ€ĐŸĐČĐ”ĐŽĐ”ĐœĐœŃ Ń€ĐŸĐ±Ń–Ń‚ Đ· ĐŸĐżŃ‚ĐžĐŒŃ–Đ·Đ°Ń†Ń–Ń— Đ”ĐœĐ”Ń€ĐłĐŸĐżĐŸŃŃ‚Đ°Ń‡Đ°ĐœĐœŃ ĐœĐ°ŃƒĐșĐŸĐČĐŸ-ĐŽĐŸŃĐ»Ń–ĐŽĐœĐŸĐłĐŸ ĐșĐŸĐŒĐżĐ»Đ”Đșсу Đ†ĐœŃŃ‚ĐžŃ‚ŃƒŃ‚Ńƒ Ń–ĐŸĐœĐŸŃŃ„Đ”Ń€Đž. Đ—Đ°ĐżŃ€ĐŸĐżĐŸĐœĐŸĐČĐ°ĐœĐŸ ĐŒĐŸĐ¶Đ»ĐžĐČі Đ·Đ°Ń…ĐŸĐŽĐž ĐŽĐ»Ń Đ·ĐœĐžĐ¶Đ”ĐœĐœŃ Đ”ĐșĐŸĐœĐŸĐŒŃ–Ń‡ĐœĐŸŃ— ĐČĐ°Ń€Ń‚ĐŸŃŃ‚Ń– ĐżŃ€ĐŸĐČĐ”ĐŽĐ”ĐœĐœŃ Đ”ĐșŃĐżĐ”Ń€ĐžĐŒĐ”ĐœŃ‚Ń–ĐČ Đ· ĐŽĐŸŃĐ»Ń–ĐŽĐ¶Đ”ĐœĐœŃ Ń–ĐŸĐœĐŸŃŃ„Đ”Ń€Đž ĐœĐ°ŃƒĐșĐŸĐČĐŸ-ĐŽĐŸŃĐ»Ń–ĐŽĐœĐŸĐłĐŸ ĐșĐŸĐŒĐżĐ»Đ”Đșсу ĐœĐ”ĐșĐŸĐłĐ”Ń€Đ”ĐœŃ‚ĐœĐŸĐłĐŸ Ń€ĐŸĐ·ŃŃ–ŃĐœĐœŃ. ĐŸŃ€ĐŸĐČĐ”ĐŽĐ”ĐœĐŸ Đ°ĐœĐ°Đ»Ń–Đ· Ń€ĐŸĐ±Ń–Ń‚ ŃŃƒŃ‡Đ°ŃĐœĐžŃ… Đ°ĐČŃ‚ĐŸŃ€Ń–ĐČ Đ· ĐŒĐ”Ń‚ĐŸŃŽ ĐżĐŸĐșĐ°Đ·Đ°Ń‚Đž, Ń‰ĐŸ піЮĐČĐžŃ‰Đ”ĐœĐœŃ ДфДĐșтоĐČĐœĐŸŃŃ‚Ń– Ń„ŃƒĐœĐșŃ†Ń–ĐŸĐœŃƒĐČĐ°ĐœĐœŃ ŃĐžŃŃ‚Đ”ĐŒ ДлДĐșŃ‚Ń€ĐŸĐżĐŸŃŃ‚Đ°Ń‡Đ°ĐœĐœŃ є Đ°ĐșŃ‚ŃƒĐ°Đ»ŃŒĐœĐŸŃŽ ĐżŃ€ĐŸĐ±Đ»Đ”ĐŒĐŸŃŽ ŃŃƒŃ‡Đ°ŃĐœĐžŃ… ĐŽĐŸŃĐ»Ń–ĐŽĐ¶Đ”ĐœŃŒ.This article presents the results of the analysis of the energy consumption modes of the incoherent scattering complex of the Institute of Ionosphere of the National Academy of Sciences and the Ministry of Education and Science of Ukraine to solve the problem of increasing the energy efficiency of a research complex and creating an energy efficient power supply system that will ensure the sustainability of scientific equipment for research programs of the National Academy of Sciences of Ukraine. The system of power supply of the complex and modes of power consumption of the complex are described. The devices of the radar system are described, as well as the most powerful consumers of electricity, which consume electricity for experimental and economic needs. The energy consumption of the incoherent scattering complex in 2013 is analyzed. Graphs of the average power consumption (daily average) and average power consumption in measurement modes were obtained and presented. The feasibility of work to optimize the energy supply of the research complex of the institute of the ionosphere is described. Possible measures are proposed to reduce the economic cost of conducting experiments on the study of the ionosphere of an incoherent scattering research complex. The analysis of the works of modern authors i s carried out in order to show that increasing the efficiency of the power supply systems is an actual problem of modern research

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

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    A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters

    Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary

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    This paper constructs the reduction of heterotic MM-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and for the boundary conditions on the bulk fields. Some general features of dualisation on a manifold with boundary are used to explain the origin of some topological terms in the action. The effect of gaugino condensation on the fermion boundary conditions leads to a `twist' in the chirality of the gravitino which can provide an uplifting mechanism in the vacuum energy to cancel the cosmological constant after moduli stabilisation.Comment: 16 pages, RevTe
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