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
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
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
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
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
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
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
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.
Pairing in two-dimensional boson-fermion mixtures
The possibilities of pairing in two-dimensional boson-fermion mixtures are
carefully analyzed. It is shown that the boson-induced attraction between two
identical fermions dominates the p-wave pairing at low density. For a given
fermion density, the pairing gap becomes maximal at a certain optimal boson
concentration. The conditions for observing pairing in current experiments are
discussedComment: 10 pages, 5 figs, revtex
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