41 research outputs found
Weakly-Interacting Bosons in a Trap within Approximate Second Quantization Approach
The theory of Bogoliubov is generalized for the case of a weakly-interacting
Bose-gas in harmonic trap. A set of nonlinear matrix equations is obtained to
make the diagonalization of Hamiltonian possible. Its perturbative solution is
used for the calculation of the energy and the condensate fraction of the model
system to show the applicability of the method.Comment: 6 pages, two figures .Presented at the International Symposium on
Quantum Fluids and Solids QFS2006 (Kyoto, Japan
Phase separation of Bose-Einstein condensates
The zero-temperature system of two dilute overlapping Bose-Einstein
condensates is unstable against long wavelength excitations if the interaction
strength between the distinguishable bosons exceeds the geometric mean of the
like-boson interaction strengths. If the condensates attract each other, the
instability is similar to the instability of the negative scattering length
condensates. If the condensates repel, they separate spatially into condensates
of equal pressure. We estimate the boundary size, surface tension and energy of
the phase separated condensate system and we discuss the implications for
double condensates in atomic traps.Comment: 11 pages, 1 figur
Augmented Lagrangian Method for Constrained Nuclear Density Functional Theory
The augmented Lagrangiam method (ALM), widely used in quantum chemistry
constrained optimization problems, is applied in the context of the nuclear
Density Functional Theory (DFT) in the self-consistent constrained Skyrme
Hartree-Fock-Bogoliubov (CHFB) variant. The ALM allows precise calculations of
multidimensional energy surfaces in the space of collective coordinates that
are needed to, e.g., determine fission pathways and saddle points; it improves
accuracy of computed derivatives with respect to collective variables that are
used to determine collective inertia; and is well adapted to supercomputer
applications.Comment: 6 pages, 3 figures; to appear in Eur. Phys. J.
Nuclear Transparency to Intermediate-Energy Protons
Nuclear transparency in the (e,e'p) reaction for 135 < Tp < 800 MeV is
investigated using the distorted wave approximation. Calculations using
density-dependent effective interactions are compared with phenomenological
optical potentials. Nuclear transparency is well correlated with proton
absorption and neutron total cross sections. For Tp < 300 MeV there is
considerable sensitivity to the choice of optical model, with the empirical
effective interaction providing the best agreement with transparency data. For
Tp > 300 MeV there is much less difference between optical models, but the
calculations substantially underpredict transparency data and the discrepancy
increases with A. The differences between Glauber and optical model
calculations are related to their respective definitions of the semi-inclusive
cross section. By using a more inclusive summation over final states the
Glauber model emphasizes nucleon-nucleon inelasticity, whereas with a more
restrictive summation the optical model emphasizes nucleon-nucleus
inelasticity; experimental definitions of the semi-inclusive cross section lie
between these extremes.Comment: uuencoded gz-compressed tar file containing revtex and bbl files and
5 postscript figures, totalling 31 pages. Uses psfi
Rhinitis in the geriatric population
The current geriatric population in the United States accounts for approximately 12% of the total population and is projected to reach nearly 20% (71.5 million people) by 2030[1]. With this expansion of the number of older adults, physicians will face the common complaint of rhinitis with increasing frequency. Nasal symptoms pose a significant burden on the health of older people and require attention to improve quality of life. Several mechanisms likely underlie the pathogenesis of rhinitis in these patients, including inflammatory conditions and the influence of aging on nasal physiology, with the potential for interaction between the two. Various treatments have been proposed to manage this condition; however, more work is needed to enhance our understanding of the pathophysiology of the various forms of geriatric rhinitis and to develop more effective therapies for this important patient population
PROJECTION DES FONCTIONS D'ONDE DE HARTREE-FOCK SUR UN MOMENT CINÉTIQUE DONNÉ DANS LES NOYAUX LÉGERS
23 niveaux des noyaux 18O, 18F, 19F et 20Ne, correspondant à des configurations 4 particules-2 trous, 4 p 1 t, 4 p, 3 p, 2 p, sont obtenus de façon satisfaisante avec la seule force de Rosenfeld, d'intensité 53,25 MeV. La projection des états Hartree-Fock sur un moment cinétique donné, comparée à la diagonalisation exacte, en donne une bonne approximation.23 energy levels of the nuclei 18O, 18F, 19F and 20Ne, corresponding to configurations of 4 particles-2 holes, 4 p 1 h, 4 p, 3 p, 2 p, are correctly reproduced with a single Rosenfeld force of 53.25 MeV strength. The angular momentum projection of the Hartree-Fock determinants, compared to exact diagonalisation, appears as a good approximation of it