19,268 research outputs found

    A Twisted Custodial Symmetry in the Two-Higgs-Doublet Model

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    In the Standard Model for electroweak interactions, the Higgs sector is known to display a "custodial" symmetry protecting the mass relation m_{W^\pm}^2=m_{W_3}^2 from large corrections. When considering extensions of the scalar sector, this symmetry has to be introduced by hand in order to pass current electroweak precision tests in a natural way. In this Letter we implement a generalized custodial symmetry in the two-Higgs-doublet model. Assuming the invariance of the potential under CP transformations, we prove the existence of a new custodial scenario characterized by m_{H^\pm}^2=m_{H^0}^2 instead of m_{H^\pm}^2=m_{A^0}^2. Consequently the pseudoscalar A^0 may be much lighter than the charged H^\pm, giving rise to interesting phenomenology.Comment: 4 pages, RevTeX

    Near infrared star counts as a test of Galactic bar structure

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    We present survey data in the narrow-band L filter (nbL), taken at UKIRT, for a total area of 277 square arcmin, roughly equally divided between four regions at zero Galactic latitude and longitudes +-4.3 deg and +-2.3 deg. The 80% completeness level for these observations is at roughly magnitude 11.0. This magnitude limit, owing to the low coefficient for interstellar extinction at this wavelength (A(nbL)=0.047 A(V)), allows us to observe bulge giants. We match the nbL-magnitudes with DENIS survey K magnitudes, and find 95 per cent of nbL sources are matched to K sources. Constructing colour-magnitude diagrams, we deredden the magnitudes and find evidence for a longitude dependent asymmetry in the source counts. We find that there are ~15% and ~5% more sources at the negative longitude than at the corresponding positive longitude, for the fields at +-4.3 deg and +-2.3 deg respectively. This is compared with the predictions of some Galactic bar models. We find an asymmetry in the expected sense, which favours gas dynamical models and the recent deconvolution of surface photometry data (Binney et al. 1991; Binney, Gerhard & Spergel 1997), over earlier treatments of photometric data (e.g. Dwek et al. 1995).Comment: 10 pages, Latex, MNRAS accepte

    Public policy and life insurance

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    Public policy ; Life insurance companies ; Insurance industry

    Counselors\u27 Social Class and Socioeconomic Status Understanding and Awareness

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    Nine licensed professional counselors participated in semi-structured interviews designed to reveal their awareness and understanding about social class and socioeconomic status (SES). Findings suggest that participants\u27 descriptions of social class and SES often are in-congruent with how they use the terms, and their awareness and understanding may be limited because of developmental factors, indicating potential clinical liabilities. The authors suggest that counselors should develop stronger social class consciousness to provide affirming counseling services and that further research on such strategies is needed

    The observable light deflection angle

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    The physical deflection angle of a light ray propagating in a space-time supplied with an asymptotically flat metric has to be expressed in terms of the impact parameter.Comment: 11 pages, 1 figur

    Priorities for Microgravity Combustion Research and Goals for Workshop Discussions

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    Several concerns motivate fundamental research: combustion-generated pollutants are re-emerging as a major problem, new combustion technologies are needed for effective energy utilization, municipal and hazardous waste incineration are needed to replace landfills and storage, new combustion technologies are needed for advanced aircraft and spacecraft propulsion systems, and current understanding of fires and explosion hazards is limited - particularly for space-craft environments. Thus, it is of interest to determine how experimentation using microgravity facilities can advance research relevant to these problems
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