1,960 research outputs found

    Electromagnetic Mass Splittings in Heavy Mesons

    Full text link
    The electromagnetic contribution to the isomultiplet mass splittings of heavy mesons is reanalyzed within the framework of the heavy mass expansion. It is shown that the leading term in the expansion is given to a good approximation by the elastic term. 1/mQ1/m_{Q}-corrections can only be estimated, the main source of uncertainty now being inelastic contributions. The 1/mQ1/m_{Q}-corrections to the elastic term turn out to be relatively small in both D and B pseudoscalar mesons.Comment: 16 pages, report CEBAF-TH-92-26, one figure not included (available if requested

    Isospin splitting in heavy baryons and mesons

    Full text link
    A recent general analysis of light-baryon isospin splittings is updated and extended to charmed baryons. The measured Σc\Sigma_c and Ξc\Xi_c splittings stand out as being difficult to understand in terms of two-body forces alone. We also discuss heavy-light mesons; though the framework here is necessarily less general, we nevertheless obtain some predictions that are not strongly model-dependent.Comment: 12 pages REVTEX 3, plus 4 uuencoded ps figures, CMU-HEP93-

    Reimagine the ICU: Healthcare Professionals’ Perspectives on How Environments (Can) Promote Patient Well-Being

    Get PDF
    Objective: This study aims (1) to understand the needs and challenges of the current intensive care unit (ICU) environments in supporting patient well-being from the perspective of healthcare professionals (HCPs) and (2) to explore the new potential of ICU environments enabled by technology.Background: Evidence-based design has yielded how the design of environments can advocate for patient well-being, and digital technology offers new possibilities for indoor environments. However, the role of technology in facilitating ICU patient well-being has been unexplored.Method: This study was conducted in two phases. First, a mixed-method study was conducted with ICU HCPs from four Dutch hospitals. The study investigated the current environmental support for care activities, as well as the factors that positively and negatively contribute to patient experience. Next, a co-creation session was held involving HCPs and health technology experts to explore opportunities for technology to support ICU patient well-being.Results: The mixed-method study revealed nine negative and eight positive patient experience factors. HCPs perceived patient emotional care as most challenging due to the ICU workload and a lack of environmental support in fulfilling patient emotional needs. The co-creation session yielded nine technology-enabled solutions to address identified challenges. Finally, drawing from insights from both studies, four strategies were introduced that guide toward creating technology to provide holistic and personalized care for patients.Conclusion: Patient experience factors are intertwined, necessitating a multifactorial approach to support patient well-being. Viewing the ICU environment as a holistic unit, our findings provide guidance on creating healing environments using technology

    Thermodynamics and Kinetic Theory of Relativistic Gases in 2-D Cosmological Models

    Get PDF
    A kinetic theory of relativistic gases in a two-dimensional space is developed in order to obtain the equilibrium distribution function and the expressions for the fields of energy per particle, pressure, entropy per particle and heat capacities in equilibrium. Furthermore, by using the method of Chapman and Enskog for a kinetic model of the Boltzmann equation the non-equilibrium energy-momentum tensor and the entropy production rate are determined for a universe described by a two-dimensional Robertson-Walker metric. The solutions of the gravitational field equations that consider the non-equilibrium energy-momentum tensor - associated with the coefficient of bulk viscosity - show that opposed to the four-dimensional case, the cosmic scale factor attains a maximum value at a finite time decreasing to a "big crunch" and that there exists a solution of the gravitational field equations corresponding to a "false vacuum". The evolution of the fields of pressure, energy density and entropy production rate with the time is also discussed.Comment: 23 pages, accepted in PR

    Analytical and experimental bearing capacities of system scaffolds

    Get PDF
    We investigated the structural behavior and bearing capacity of system scaffolds. The research showed that the critical load of a system scaffold structure without diagonal braces is similar to that of a door-shaped steel scaffold structure. Joint stiffness between vertical props in system scaffolds can be defined based on a comparison between analytical and experimental results. When the number of scaffold stories increases, the critical loads of system scaffolds decrease. Diagonal braces markedly enhance the critical load of system scaffolds. The coupling joint position between vertical props should be kept away from story-to-story joints to prevent a reduction in critical loads. The critical load of a system scaffold decreases as the quantity of extended vertical props at the bottom of the structure increases. A large Christmas tree set up by system scaffolds under various loads was used as an example for analysis and to check the design of system scaffolds

    Higgsino Dark Matter in a SUGRA Model with Nonuniversal Gaugino Masses

    Get PDF
    We study a specific SUGRA model with nonuniversal gaugino masses as an alternative to the minimal SUGRA model in the context of supersymmetric dark matter. The lightest supersymmetric particle in this model comes out to be a Higgsino dominated instead of a bino dominated lightest neutralino. The thermal relic density of this Higgsino dark matter is somewhat lower than the cosmologically favoured range, which means it may be only a subdominant component of the cold dark matter. Nonetheless, it predicts favourable rates of indirect detection, which can be seen in square-km size neutrino telescopes.Comment: Version to appear in Phys. Rev. D. A few references added in the bibliography and a comment added in Section 2. LaTex, 16 pages, 4 figure

    Focus Point SUSY at the LHC Revisited

    Full text link
    The estimation of the backgrounds for gluino signals in focus point supersymmetry is extended by including the backgrounds from the production of four third generation quarks in the analysis. We find that these backgrounds are negligible if one uses the strong selection criteria proposed in the literature (including this analysis) for heavy gluino searches. Softer selection criteria often recommended for lighter gluino searches yield backgrounds which are small but numerically significant. We have also repeated the more conventional background calculations and compared our results with the other groups. We find that the size of the total residual background estimated by different groups using different event generators and hard kinematical cuts agree approximately. In view of the theoretical uncertainties in the leading order signal and background cross sections mainly due to the choice of the QCD scale, the gluino mass reach at the LHC cannot be pinpointed. However, requiring a signal with ≄3\rm\geq 3 tagged b-jets (instead of the standard choice of ≄2\rm\geq 2) it is shown that gluino masses close to 2 TeV can be probed at the LHC for a range of reasonable choices of the QCD scale for an integrated luminosity of 300 fb−1^{-1}.Comment: 17 pages, 4 figures, minor typos correctio
    • 

    corecore