873 research outputs found

    Identifying the quark content of the isoscalar scalar mesons f_0(980), f_0(1370), and f_0(1500) from weak and electromagnetic processes

    Get PDF
    The assignments of the isoscalar scalar mesons f0(980), f0(1370), and f0(1500) in terms of their qqbar substructure is still a matter of heated dispute. Here we employ the weak and electromagnetic decays D(s)(+) to f0+pi(+) and f0 two-photon decays, respectively, to identify the f0(980) and f0(1500) as mostly ssbar, and the f0(1370) as dominantly nonstrange, in agreement with previous work. The two-photon decays can be satisfactorily described with quark as well as with meson loops, though the latter ones provide a less model-dependent and more quantitative description.Comment: v1, 15 pages, plain LaTeX, 1 eps figure. v2, 18 pages, plain LaTeX (figure included). More discussion, especially on the f0(1370) and its empirical two-photon widt

    COMBAR COST EU. A mobile application proposal

    Get PDF
    Diagnosis and treatment options/strategies for helminth parasitic diseases are not standardized globally, or even across Europe, due to factors such as epidemiology, resources availability, socio-economics, and the lack of adequate information. Good communication of options can help to overcome some of these problems. In this sense, it is proposed to develop a mobile application (Abozeid et al., 2021) that allows the tailoring, and sharing, of knowledge (Abu-El-Noor et al., 2021; Kunkel et al., 2021) related to the various diagnoses and treatments in a format appropriate for all stakeholders (e.g. farmers, veterinarians, universities, researchers, laboratories, industries). The proposal aims to present the theoretical functionalities for the creation of a mobile application (Muashekele et al., 2021), the application should have a sequence of options that must be grounded in theoretical requirements. First of all, there is a necessity to have inputs standardized by the application (e.g. country/region, applicable legislation, animal typology, disease characteristics, symptoms) that should be entered into the application. The aim is to provide a range of tailored options to the end-user. Second, given the user's choices, the application can offer information and guidelines (including veterinarians available, laboratories, diagnosis, treatments, stores, among others). It is highlighted that the main gain may be the collection of information, whenever the user allows it. Finally, considering that most farmers use the language of their country, it is crucial to have the application in different European languages.info:eu-repo/semantics/publishedVersio

    Finite temperature theory of the trapped two dimensional Bose gas

    Full text link
    We present a Hartree-Fock-Bogoliubov (HFB) theoretical treatment of the two-dimensional trapped Bose gas and indicate how semiclassical approximations to this and other formalisms have lead to confusion. We numerically obtain results for the fully quantum mechanical HFB theory within the Popov approximation and show that the presence of the trap stabilizes the condensate against long wavelength fluctuations. These results are used to show where phase fluctuations lead to the formation of a quasicondensate.Comment: 4 pages, 3 figure

    Kinetic model of II-VI(001) semiconductor surfaces: Growth rates in atomic layer epitaxy

    Get PDF
    We present a zinc-blende lattice gas model of II-VI(001) surfaces, which is investigated by means of Kinetic Monte Carlo (KMC) simulations. Anisotropic effective interactions between surface metal atoms allow for the description of, e.g., the sublimation of CdTe(001), including the reconstruction of Cd-terminated surfaces and its dependence on the substrate temperature T. Our model also includes Te-dimerization and the potential presence of excess Te in a reservoir of weakly bound atoms at the surface. We study the self-regulation of atomic layer epitaxy (ALE) and demonstrate how the interplay of the reservoir occupation with the surface kinetics results in two different regimes: at high T the growth rate is limited to 0.5 layers per ALE cycle, whereas at low enough T each cycle adds a complete layer of CdTe. The transition between the two regimes occurs at a characteristic temperature and its dependence on external parameters is studied. Comparing the temperature dependence of the ALE growth rate in our model with experimental results for CdTe we find qualitative agreement.Comment: 9 pages (REVTeX), 8 figures (EPS). Content revised, references added, typos correcte

    Surgical Apgar Score (SAS) Predicts Perioperative Morbidity and Length of Stay in Patients Undergoing Esophagectomy at a High-Volume Center

    Get PDF
    Background: Esophagectomy is a procedure that carries considerable morbidity. Many studies have evaluated factors to predict patients at risk and improve clinical outcomes. The aim of this study was to determine whether the SAS predicts complications, length of stay, and anastomotic leak for patients undergoing esophagectomy at a high-volume institution.https://jdc.jefferson.edu/surgeryposters/1002/thumbnail.jp

    Adiabatic Output Coupling of a Bose Gas at Finite Temperatures

    Get PDF
    We develop a general theory of adiabatic output coupling from trapped atomic Bose-Einstein Condensates at finite temperatures. For weak coupling, the output rate from the condensate, and the excited levels in the trap, settles in a time proportional to the inverse of the spectral width of the coupling to the output modes. We discuss the properties of the output atoms in the quasi-steady-state where the population in the trap is not appreciably depleted. We show how the composition of the output beam, containing condensate and thermal component, may be controlled by changing the frequency of the output coupler. This composition determines the first and second order coherence of the output beam. We discuss the changes in the composition of the bose gas left in the trap and show how nonresonant output coupling can stimulate either the evaporation of thermal excitations in the trap or the growth of non-thermal excitations, when pairs of correlated atoms leave the condensate.Comment: 22 pages, 6 Figs. To appear in Physical Review A All the typos from the previous submission have been fixe

    f0(980) meson as a K bar K molecule in a phenomenological Lagrangian approach

    Full text link
    We discuss a possible interpretation of the f0(980) meson as a hadronic molecule - a bound state of K and bar K mesons. Using a phenomenological Lagrangian approach we calculate the strong f0(980) to pi pi and electromagnetic f0(980) to gamma gamma decays. The compositeness condition provides a self-consistent method to determine the coupling constant between f0 and its constituents, K and bar K. Form factors governing the decays of the f0(980) are calculated by evaluating the kaon loop integrals. The predicted f0(980) to pi pi and f0(980) to gamma gamma decay widths are in good agreement with available data and results of other theoretical approaches.Comment: 21 pages, 11 figures, revised version accepted for publication in Eur. Phys. J.
    corecore