2,978 research outputs found

    Evaluation of the Union Learning Fund year 4

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    Conformal Symmetry and Unification

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    The Weyl-Weinberg-Salam model is presented. It is based on the local conformal gauge symmetry. The model identifies the Higgs scalar field in SM with the Penrose-Chernikov-Tagirov scalar field of the conformal theory of gravity. Higgs mechanism for generation of particle masses is replaced by the originated in Weyl's ideas conformal gauge scale fixing. Scalar field is no longer a dynamical field of the model and does not lead to quantum particle-like excitations that could be observed in HE experiments. Cosmological constant is naturally generated by the scalar quadric term. The model admits Weyl vector bosons that can mix with photon and weak bosons.Comment: 10 pages, latex, aipproc.sty, no figures, talk given at the International Conference Particles, Fields and Gravitation, Lodz, April 199

    MIPAS IMK/IAA CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements: accuracy, precision and long-term stability

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    Eckert, E. et. al.Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MIPAS/ 4.62 and MIPAS/5.02 to MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). These profiles have been compared to measurements taken by the balloon-borne cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS-STRatospheric aircraft (MIPAS-STR), the satellite-borne Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the High Resolution Dynamic Limb Sounder (HIRDLS), as well as the groundbased Halocarbon and other Atmospheric Trace Species (HATS) network for the reduced spectral resolution period (RR: January 2005-April 2012) of MIPAS. ACE-FTS, MkIV and HATS also provide measurements during the high spectral resolution period (full resolution, FR: July 2002-March 2004) and were used to validate MIPAS CFC-11 and CFC-12 products during that time, as well as profiles from the Improved Limb Atmospheric Spectrometer, ILAS-II. In general, we find that MIPAS shows slightly higher values for CFC-11 at the lower end of the profiles (below ∼15 km) and in a comparison of HATS ground-based data and MIPAS measurements at 3 km below the tropopause. Differences range from approximately 10 to 50 pptv (∼5-20 %) during the RR period. In general, differences are slightly smaller for the FR period. An indication of a slight high bias at the lower end of the profile exists for CFC-12 as well, but this bias is far less pronounced than for CFC-11 and is not as obvious in the relative differences between MIPAS and any of the comparison instruments. Differences at the lower end of the profile (below ∼15 km) and in the comparison of HATS and MIPAS measurements taken at 3 km below the tropopause mainly stay within 10-50 pptv (corresponding to ∼2-10%for CFCPublished 12) for the RR and the FR period. Between ∼15 and 30 km, most comparisons agree within 10-20 pptv (10-20 %), apart from ILAS-II, which shows large differences above ∼17 km. Overall, relative differences are usually smaller for CFC-12 than for CFC-11. For both species - CFC-11 and CFC-12 - we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS profiles have a maximum in their mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Comparisons of the standard deviation in a quiescent atmosphere (polar summer) show that only the CFC-12 FR error budget can fully explain the observed variability, while for the other products (CFC-11 FR and RR and CFC-12 RR) only two-thirds to three-quarters can be explained. Investigations regarding the temporal stability show very small negative drifts in MIPAS CFC-11 measurements. These instrument drifts vary between ∼1 and 3% decade-1. For CFC-12, the drifts are also negative and close to zero up to ∼30 km. Above that altitude, larger drifts of up to ∼50% decade-1 appear which are negative up to ∼35 km and positive, but of a similar magnitude, above. © Author(s) 2016.IMK data analysis was supported by DLR under contract number 50EE0901. MIPAS level 1B data were provided by ESA. We acknowledge support by Deutsche Forschungsgemeinschaft and Open Access Publishing Fund of Karlsruhe Institute of Technology. The Atmospheric Chemistry Experiment (ACE), also known as SCISAT, is a Canadian-led mission mainly supported by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada. Work at the Jet Propulsion Laboratory, California Institute of Technology, was carried out under contract with the National Aeronautics and Space Administration. Data collection and analysis of MIPAS-STR data used here were supported by the EU-project RECONCILE (grant no. 15 226365-FP7-ENV-2008-1) and the BMBF-project ENVIVAL-Life (DLR grant no. 50EE0841).Peer reviewe

    On determination of the large-1x{1\over x} gluon distribution at HERA

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    We discuss corrections to the Leading-LogQ2Q^{2} relationships between the gluon density g(x,Q2)g(x,Q^{2}) and FL(x,Q2),FT(x,Q2)/logQ2F_{L}(x,Q^{2}),\,\partial F_{T}(x,Q^{2}) /\partial \log Q^{2} in the HERA range of large 1x{1\over x}. We find that the above quantities probe the gluon density g(x,QT,L2)g(x,Q_{T,L}^{2}) at QT,L2=CT,LQ2Q_{T,L}^{2}=C_{T,L}Q^{2}, with the Q2Q^{2}-rescaling factors CT2.2C_{T}\approx 2.2 and CL0.42C_{L}\approx 0.42. The possibility of treating charm as an active flavour is critically re-examined.Comment: 12 pages, 4 figures upon the request from [email protected], J\"ulich preprint KFA-IKP(TH)-1994-12. Some misprints and ordering of references correcte

    Ozone profiles in the high-latitude stratosphere and lower mesosphere measured by the Improved Limb Atmospheric Spectrometer (ILAS)-II: comparison with other satellite sensors and ozonesondes

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    A solar occultation sensor, the Improved Limb Atmospheric Spectrometer (ILAS)-II, measured 5890 vertical profiles of ozone concentrations in the stratosphere and lower mesosphere and of other species from January to October 2003. The measurement latitude coverage was 54–71°N and 64–88°S, which is similar to the coverage of ILAS (November 1996 to June 1997). One purpose of the ILAS-II measurements was to continue such high-latitude measurements of ozone and its related chemical species in order to help accurately determine their trends. The present paper assesses the quality of ozone data in the version 1.4 retrieval algorithm, through comparisons with results obtained from comprehensive ozonesonde measurements and four satellite-borne solar occultation sensors. In the Northern Hemisphere (NH), the ILAS-II ozone data agree with the other data within ±10% (in terms of the absolute difference divided by its mean value) at altitudes between 11 and 40 km, with the median coincident ILAS-II profiles being systematically up to 10% higher below 20 km and up to 10% lower between 21 and 40 km after screening possible suspicious retrievals. Above 41 km, the negative bias between the NH ILAS-II ozone data and the other data increases with increasing altitude and reaches 30% at 61–65 km. In the Southern Hemisphere, the ILAS-II ozone data agree with the other data within ±10% in the altitude range of 11–60 km, with the median coincident profiles being on average up to 10% higher below 20 km and up to 10% lower above 20 km. Considering the accuracy of the other data used for this comparative study, the version 1.4 ozone data are suitably used for quantitative analyses in the high-latitude stratosphere in both the Northern and Southern Hemisphere and in the lower mesosphere in the Southern Hemisphere
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