95,533 research outputs found

    Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′

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    First evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)

    SunSmart? Skin cancer knowledge and preventive behaviour in a British population representative sample

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    The incidence of skin cancer has risen rapidly in the UK over the last 20 years, prompting public health organizations to try and raise awareness of the dangers of sun exposure and the need to practice sun-safe behaviour. This study aimed to assess baseline levels of sun-safe knowledge and behaviour in a British population-representative sample, prior to the launch of Cancer Research UK's 'SunSmart' campaign. A face-to-face survey was conducted through the Office for National Statistics as part of their Omnibus survey. In total, 1848 men and women aged 18 and over were interviewed. Knowledge of what to do to reduce skin cancer risk was modest. Two-thirds mentioned avoiding the sun by seeking shade, 50% mentioned covering up and only 43% said to use high factor sunscreen. Practice of sun-safe behaviours was also poor, with only one-third saying they sought shade, covered up or used high factor sunscreen to protect themselves from the sun. Men and those from lower socioeconomic groups were least informed and least likely to report using sun-protective behaviours. Increases in both knowledge and use of appropriate sun-protective behaviours are needed if skin cancer incidence rates are to decrease

    Extension of the sun-synchronous Orbit

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    Through careful consideration of the orbit perturbation force due to the oblate nature of the primary body a secular variation of the ascending node angle of a near-polar orbit can be induced without expulsion of propellant. Resultantly, the orbit perturbations can be used to maintain the orbit plane in, for example, a near-perpendicular (or at any other angle) alignment to the Sun-line throughout the full year of the primary body; such orbits are normally termed Sun-synchronous orbits [1, 2]. Sun-synchronous orbits about the Earth are typically near-circular Low-Earth Orbits (LEOs), with an altitude of less than 1500 km. It is normal to design a LEO such that the orbit period is synchronised with the rotation of the Earth‟s surface over a given period, such that a repeating ground-track is established. A repeating ground-track, together with the near-constant illumination conditions of the ground-track when observed from a Sun-synchronous orbit, enables repeat observations of a target over an extended period under similar illumination conditions [1, 2]. For this reason, Sun-synchronous orbits are extensively used by Earth Observation (EO) platforms, including currently the Environmental Satellite (ENVISAT), the second European Remote Sensing satellite (ERS-2) and many more. By definition, a given Sun-synchronous orbit is a finite resource similar to a geostationary orbit. A typical characterising parameter of a Sun-synchronous orbit is the Mean Local Solar Time (MLST) at descending node, with a value of 1030 hours typical. Note that ERS-1 and ERS-2 used a MLST at descending node of 1030 hours ± 5 minutes, while ENVISAT uses a 1000 hours ± 5 minutes MLST at descending node [3]. Following selection of the MLST at descending node and for a given desired repeat ground-track, the orbit period and hence the semi-major axis are fixed, thereafter assuming a circular orbit is desired it is found that only a single orbit inclination will enable a Sun-synchronous orbit [2]. As such, only a few spacecraft can populate a given repeat ground-track Sun-synchronous orbit without compromise, for example on the MLST at descending node. Indeed a notable feature of on-going studies by the ENVISAT Post launch Support Office is the desire to ensure sufficient propellant remains at end-of-mission for re-orbiting to a graveyard orbit to ensure the orbital slot is available for future missions [4]. An extension to the Sun-synchronous orbit is considered using an undefined, non-orientation constrained, low-thrust propulsion system. Initially the low-thrust propulsion system will be considered for the free selection of orbit inclination and altitude while maintaining the Sun-synchronous condition. Subsequently the maintenance of a given Sun-synchronous repeat-ground track will be considered, using the low-thrust propulsion system to enable the free selection of orbit altitude. An analytical expression will be developed to describe these extensions prior to then validating the analytical expressions within a numerical simulation of a spacecraft orbit. Finally, an analysis will be presented on transfer and injection trajectories to these orbits

    Search for f(J)(2220) in radiative J/psi decays

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    We present a search for f(J)(2220) production in radiative J/psi --> gamma f(J)(2220) decays using 460 fb(-1) of data collected with the BABAR detector at the SLAC PEP-II e(+)e(-) collider. The f(J)(2220) is searched for in the decays to K+K- and (KSKS0)-K-0. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/psi --> gamma f(J)(2220) and f(J)(2220) --> K+K-((KSKS0)-K-0) as a function of spin and helicity are set at the level of 10(-5), below the central values reported by the Mark III experiment

    POLAR investigation of the Sun—POLARIS

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    The POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75° with respect to solar equator. This challenging orbit is made possible by the challenging development of solar sail propulsion. This first extended view of the high-latitude regions of the Sun will enable crucial observations not possible from the ecliptic viewpoint or from Solar Orbiter. While Solar Orbiter would give the first glimpse of the high latitude magnetic field and flows to probe the solar dynamo, it does not have sufficient viewing of the polar regions to achieve POLARIS’s primary objective: determining the relation between the magnetism and dynamics of the Sun’s polar regions and the solar cycle

    A grounded theory of female adolescent behaviour in the sun: comfort matters.

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    The aim of the research was to generate a grounded theory to explain the behaviour of young women in the sun. The study sought to explore the sun-related experiences of young women in order to gain new insights into the influences upon them. The study was qualitative by design and utilised grounded theory method as developed by Glaser. Twenty female participants, aged 14 to 17 years old were included in the study. They formed six groups. Thirteen interviews were carried out with the groups and six one-to one interviews took place with individuals. All interviews were semi-structured and were based upon the participants' experiences of being in the sun. Data was analysed using the constant comparative method of data analysis, concordant with Glaserian grounded theory method. Five explanatory categories emerged from the data; Fitting In, Being Myself, Being Physically Comfortable, Slipping Up and a core category of Being Comfortable. One of the issues that emerged was that some young women believed their social acceptance depended on their appearance and they conformed to this end. The theory, derived from the categories, proposes that when in the sun, young women direct their activities toward meeting physical and psychosocial comfort needs. Comfort matters to them because it has implications for their wellbeing. This thesis contributes to the literature about the behaviours of young women in the sun. By increasing understanding of the factors that influence them, it also adds to the body of knowledge related to the primary prevention of skin cancer with teenage girls in the United Kingdom. The outcome of the research and its contribution to knowledge is a grounded theory, which explains the basis of the behaviours of young women in the sun. It appears that no other study has explored the experiences of UK adolescent females specifically, in a qualitative way and with the intention of producing a theory to explain them

    [Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]

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    Newspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.

    Erratum: “Setup for meV-resolution inelastic X-ray scattering measurements and X-ray diffraction at the Matter in Extreme Conditions endstation at the Linac Coherent Light Source” (Review Of Scientific Instruments (2018) 89 (10F104) DOI: 10.1063/1.5039329)

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    In the original paper1 the co-author E. J. Gamboa was erroneously omitted. The corrected author list is identical to that of this erratum, and repeated below for clarity: E. E. McBride,1,2,a) T. G. White,3 A. Descamps,1,4 L. B. Fletcher,1 K. Appel,2 F. Condamine,5,6 C. B. Curry,1,7 F. Dallari,8 S. Funk,9 E. Galtier,1 E. J. Gamboa,1 M. Gauthier,1 S. Goede,2 J. B. Kim,1 H. J. Lee,1 B. K. Ofori-Okai,1,10 M. Oliver,11 A. Rigby,11 C. Schoenwaelder,1,9, P. Sun,1 Th. Tschentscher,2 B. B. L. Witte,1,12 U. Zastrau,2 G. Gregori,11 B. Nagler,1 J. Hastings,1 S. H. Glenzer,1 and G. Monaco8 1 SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA 2 European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany 3 University of Nevada at Reno, Reno, Nevada 89506, USA 4 Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305, USA 5 Sorbonne Universits, UPMC, LULI, UMR 7605, Case 128, 4 Place Jussieu, 75252 Paris Cedex 05, France 6 LULI, Ecole Polytechnique, CEA-CNRS-UPS, 91228 Palaiseau, France 7 Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada 8 Dipartimento di Fisica, Universit`a di Trento, via Sommarive 14, 38123 Povo, TN, Italy 9 Friedrich-Alexander-Universitat Erlangen-N ̈urnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, D-91058 Erlangen, Germany 10 Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA 11 Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom 12 Universit ̈at Rostock, Institut f ̈ur Physik, D-18051 Rostock, Germany
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