8,026 research outputs found
Properties of isocalar-pair condensates
It is pointed out that the ground state of n neutrons and n protons in a
single-j shell, interacting through an isoscalar (T=0) pairing force, is not
paired, J=0, but rather spin-aligned, J=n. This observation is explained in the
context of a model of isoscalar P (J=1) pairs, which is mapped onto a system of
p bosons, leading to an approximate analytic solution of the isoscalar-pairing
limit in jj coupling.Comment: 7 pages, 3 figures, 1 tabl
A giant mystery in giant cell myocarditis: navigating diagnosis, immunosuppression, and mechanical circulatory support.
Giant cell myocarditis is a rare but often devastating diagnosis. Advances in cardiac imaging and mechanical circulatory support have led to earlier and more frequent diagnoses and successful management. This disease state has wide variation in acuity of presentation, and consequently, optimal treatment ranging from intensity and type of immunosuppression to mechanical circulatory support is not well defined. The following case describes the management of a patient with an unusual presentation of giant cell myocarditis over a 10 year course of advanced heart failure therapies and immunomodulatory support. This case highlights emerging concepts in the management of giant cell myocarditis including sub-acute presentations, challenges in diagnosis, and treatment modalities in the modern era
Collective T=0 pairing in N=Z nuclei? Pairing vibrations around 56Ni revisited
We present a new analysis of the pairing vibrations around 56Ni, with
emphasis on odd-odd nuclei. This analysis of the experimental excitation
energies is based on the subtraction of average properties that include the
full symmetry energy together with volume, surface and Coulomb terms. The
results clearly indicate a collective behavior of the isovector pairing
vibrations and do not support any appreciable collectivity in the isoscalar
channel.Comment: RevTeX, two-column, 5 pages, 4 figure
Relative spins and excitation energies of superdeformed bands in 190Hg: Further evidence for octupole vibration
An experiment using the Eurogam Phase II gamma-ray spectrometer confirms the
existence of an excited superdeformed (SD) band in 190Hg and its very unusual
decay into the lowest SD band over 3-4 transitions. The energies and dipole
character of the transitions linking the two SD bands have been firmly
established. Comparisons with RPA calculations indicate that the excited SD
band can be interpreted as an octupole-vibrational structure.Comment: 12 pages, latex, 4 figures available via WWW at
http://www.phy.anl.gov/bgo/bc/hg190_nucl_ex.htm
51 Eri and GJ 3305: A 10-15 Myr old binary star system at 30 parsecs
Following the suggestion of Zuckerman et al. (2001, ApJ, 562, L87), we
consider the evidence that 51 Eri (spectral type F0) and GJ 3305 (M0),
historically classified as unrelated main sequence stars in the solar
neighborhood, are instead a wide physical binary system and members of the
young beta Pic moving group (BPMG). The BPMG is the nearest (d < 50 pc) of
several groups of young stars with ages around 10 Myr that are kinematically
convergent with the Oph-Sco-Cen Association (OSCA), the nearest OB star
association. Combining SAAO optical photometry, Hobby-Eberly Telescope
high-resolution spectroscopy, Chandra X-ray data, and UCAC2 catalog kinematics,
we confirm with high confidence that the system is indeed extremely young. GJ
3305 itself exhibits very strong magnetic activity but has rapidly depleted
most of its lithium. The 51 Eri/GJ 3305 system is the westernmost known member
of the OSCA, lying 110 pc from the main subgroups. The system is similar to the
BPMG wide binary HD 172555/CD -64d1208 and the HD 104237 quintet, suggesting
that dynamically fragile multiple systems can survive the turbulent
environments of their natal giant molecular cloud complexes, while still being
imparted high dispersion velocities. Nearby young systems such as these are
excellent targets for evolved circumstellar disk and planetary studies, having
stellar ages comparable to that of the late phases of planet formation.Comment: 27 pages, 7 figures. Accepted for publication in the Astronomical
Journal. For a version with high resolution figures, see
http://www.astro.psu.edu/users/edf/51Eri.pd
Superdeformed rotational bands in the Mercury region; A Cranked Skyrme-Hartree-Fock-Bogoliubov study
A study of rotational properties of the ground superdeformed bands in \Hg{0},
\Hg{2}, \Hg{4}, and \Pb{4} is presented. We use the cranked
Hartree-Fock-Bogoliubov method with the {\skm} parametrization of the Skyrme
force in the particle-hole channel and a seniority interaction in the pairing
channel. An approximate particle number projection is performed by means of the
Lipkin-Nogami prescription. We analyze the proton and neutron quasiparticle
routhians in connection with the present information on about thirty presently
observed superdeformed bands in nuclei close neighbours of \Hg{2}.Comment: 26 LaTeX pages, 14 uuencoded postscript figures included, Preprint
IPN-TH 93-6
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