446 research outputs found
Spectroscopic distinction between the normal state pseudogap and the superconducting gap of cuprate high T_{c} superconductors
We report on broad-band infrared ellipsometry measurements of the c-axis
conductivity of underdoped RBa_{2}Cu_{3}O_{7-d} (R=Y, Nd, and La) single
crystals. Our data provide a detailed account of the spectral weight (SW)
redistributions due to the normal state pseudogap (PG) and the superconducting
(SC) gap. They show that these phenomena involve different energy scales,
exhibit distinct doping dependencies and thus are likely of different origin.
In particular, the SW redistribution in the PG state closely resembles the one
of a conventional charge- or spin density wave (CDW or SDW) system.Comment: 4 pages, 4 figure
Manifestation of pseudogap in ab-plane optical characteristics
A model in which a gap forms in the renormalized electronic density of state
(DOS) with missing states recovered just above the pseudogap , is
able to give a robust description of the striking, triangular like, peak seen
in the real part of the optical self-energy of underdoped cuprates. We use this
model to explore the effect of the pseudogap on the real part of the optical
conductivity and on the partial sum rule associated with it. An important
result is that the optical spectral weight redistributes over a much larger
frequency window than it does in the DOS.Comment: 12 pages, 3 figures. Submitted to Journal of Physics: Condensed
Matte
Co-existing structures in 105Ru
New positive-parity states, having a band-like structure, were observed in
105Ru. The nucleus was produced in induced fission reaction and the prompt
gamma-rays, emitted from the fragments, were detected by the EUROBALL III
multi-detector array. The partial scheme of excited 105Ru levels is analyzed
within the Triaxial-Rotor-plus-Particle approach
Production of new neutron-rich isotopes of heavy elements in fragmentation reactions of U projectiles at 1 A GeV
The production of heavy neutron-rich nuclei has been investigated using cold
fragmentation reactions of U projectiles at relativistic energies. The
experiment performed at the high-resolving-power magnetic spectrometer FRS at
GSI allowed to identify 45 new heavy neutron-rich nuclei: Pt,
Au, Hg, Tl, Pb, Bi,
Po, At, Rn and Fr. The production
cross sections of these nuclei were also determined and used to benchmark
reaction codes that predict the production of nuclei far from stability.Comment: 5 pages, 2 figure
Penile Epidermal Inclusion Cyst
We report a case of epidermal inclusion cyst in a 32-year-old male. This was a complication of circumcision that was neglected over years to form stones and urethrocutaneous fistula. Complete excision of the cyst and repair of the fistula were performed successfully. Histopathological examination confirmed our diagnosis
Ground-State Electromagnetic Moments of Calcium Isotopes
High-resolution bunched-beam collinear laser spectroscopy was used to measure
the optical hyperfine spectra of the Ca isotopes. The ground state
magnetic moments of Ca and quadrupole moments of Ca were
measured for the first time, and the Ca ground state spin was
determined in a model-independent way. Our results provide a critical test of
modern nuclear theories based on shell-model calculations using
phenomenological as well as microscopic interactions. The results for the
neutron-rich isotopes are in excellent agreement with predictions using
interactions derived from chiral effective field theory including three-nucleon
forces, while lighter isotopes illustrate the presence of particle-hole
excitations of the Ca core in their ground state.Comment: Accepted as a Rapid Communication in Physical Review
Nuclear spins, magnetic moments and quadrupole moments of Cu isotopes from N = 28 to N = 46: probes for core polarization effects
Measurements of the ground-state nuclear spins, magnetic and quadrupole
moments of the copper isotopes from 61Cu up to 75Cu are reported. The
experiments were performed at the ISOLDE facility, using the technique of
collinear laser spectroscopy. The trend in the magnetic moments between the
N=28 and N=50 shell closures is reasonably reproduced by large-scale
shell-model calculations starting from a 56Ni core. The quadrupole moments
reveal a strong polarization of the underlying Ni core when the neutron shell
is opened, which is however strongly reduced at N=40 due to the parity change
between the and orbits. No enhanced core polarization is seen beyond
N=40. Deviations between measured and calculated moments are attributed to the
softness of the 56Ni core and weakening of the Z=28 and N=28 shell gaps.Comment: 13 pagers, 19 figures, accepted by Physical Review
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