149 research outputs found
Effect of ablation product absorption and line transitions on shock layer radiative transport
Ablation product absorption and line transitions effects on shock layer radiative transport around blunt bod
Convective and radiative heat transfer during superorbital entry
Convective and radiative heat transfer to space vehicles entering planetary atmospheres at superorbital velocitie
Nonlocal calculation for nonstrange dibaryons and tribaryons
We study the possible existence of nonstrange dibaryons and tribaryons by
solving the bound-state problem of the two- and three-body systems composed of
nucleons and deltas. The two-body systems are , , and
, while the three-body systems are , ,
, and . We use as input the nonlocal ,
, and potentials derived from the chiral quark cluster
model by means of the resonating group method. We compare with previous results
obtained from the local version based on the Born-Oppenheimer approximation.Comment: 19 pages. To be published in Physical Review
Polarization transfer in the O reaction at forward angles and structure of the spin-dipole resonances
Cross sections and polarization transfer observables in the O
reactions at 392 MeV were measured at several angles between
0 and 14. The non-spin-flip () and spin-flip
() strengths in transitions to several discrete states and broad
resonances in O were extracted using a model-independent method. The
giant resonances in the energy region of 27 MeV were found to be
predominantly excited by transitions. The strength distribution
of spin-dipole transitions with and were deduced.
The obtained distribution was compared with a recent shell model calculation.
Experimental results are reasonably explained by distorted-wave impulse
approximation calculations with the shell model wave functions.Comment: 28 pages RevTex, including 9 figures, to be published in Phys. Rev.
C.; a typo in Eq. (3b) was correcte
Nuclear Force from Monte Carlo Simulations of Lattice Quantum Chromodynamics
The nuclear force acting between protons and neutrons is studied in the Monte
Carlo simulations of the fundamental theory of the strong interaction, the
quantum chromodynamics defined on the hypercubic space-time lattice. After a
brief summary of the empirical nucleon-nucleon (NN) potentials which can fit
the NN scattering experiments in high precision, we outline the basic
formulation to derive the potential between the extended objects such as the
nucleons composed of quarks. The equal-time Bethe-Salpeter amplitude is a key
ingredient for defining the NN potential on the lattice. We show the results of
the numerical simulations on a lattice with the lattice spacing fm (lattice volume (4.4 fm)) in the quenched approximation.
The calculation was carried out using the massively parallel computer Blue
Gene/L at KEK. We found that the calculated NN potential at low energy has
basic features expected from the empirical NN potentials; attraction at long
and medium distances and the repulsive core at short distance. Various future
directions along this line of research are also summarized.Comment: 13 pages, 4 figures, version accepted for publication in
"Computational Science & Discovery" (IOP
Quark-model study of few-baryon systems
We review the application of non-relativistic constituent quark models to
study one, two and three non-strange baryon systems. We present results for the
baryon spectra, potentials and observables of the NN, N,
and NN systems, and also for the binding energies of three
non-strange baryon systems. We make emphasis on observable effects related to
quark antisymmetry and its interplay with quark dynamics.Comment: 82 pages, 36 figures, 18 tables. Accepted for publication in Reports
on Progress in Physic
Microwave Current Imaging in Passive HTS Components by Low-Temperature Laser Scanning Microscopy (LTLSM)
We have used the LTLSM technique for a spatially resolved investigation of
the microwave transport properties, nonlinearities and material inhomogeneities
in an operating coplanar waveguide YBa_2Cu_3O_{7-\delta} (YBCO) microwave
resonator on an LaAlO_3 (LAO) substrate. The influence of twin-domain blocks,
in-plane rotated grains, and micro-cracks in the YBCO film on the nonuniform rf
current distribution were measured with a micrometer-scale spatial resolution.
The impact of the peaked edge currents and rf field penetration into weak links
on the linear device performance were studied as well. The LTLSM capabilities
and its future potential for non-destructive characterization of the microwave
properties of superconducting circuits are discussed.Comment: 8 pages, 9 figures, 2-column format, presented at High Temperature
Superconductors in High Frequency Fields 2004, Journal of Superconductivity
(in press
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