189 research outputs found
Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u
We present a new global optical potential (GOP) for nucleus-nucleus systems,
including neutron-rich and proton-rich isotopes, in the energy range of MeV/u. The GOP is derived from the microscopic folding model with the
complex -matrix interaction CEG07 and the global density presented by S{\~
a}o Paulo group. The folding model well accounts for realistic complex optical
potentials of nucleus-nucleus systems and reproduces the existing elastic
scattering data for stable heavy-ion projectiles at incident energies above 50
MeV/u. We then calculate the folding-model potentials (FMPs) for projectiles of
even-even isotopes, C, O, Ne, Mg,
Si, S, Ar, and Ca, scattered by stable
target nuclei of C, O, Si, Ca Ni, Zr,
Sn, and Pb at the incident energy of 50, 60, 70, 80, 100, 120,
140, 160, 180, 200, 250, 300, 350, and 400 MeV/u. The calculated FMP is
represented, with a sufficient accuracy, by a linear combination of 10-range
Gaussian functions. The expansion coefficients depend on the incident energy,
the projectile and target mass numbers and the projectile atomic number, while
the range parameters are taken to depend only on the projectile and target mass
numbers. The adequate mass region of the present GOP by the global density is
inspected in comparison with FMP by realistic density. The full set of the
range parameters and the coefficients for all the projectile-target
combinations at each incident energy are provided on a permanent open-access
website together with a Fortran program for calculating the microscopic-basis
GOP (MGOP) for a desired projectile nucleus by the spline interpolation over
the incident energy and the target mass number.Comment: 25 pages, 13 figure
Recent results from the Tokyo axion helioscope experiment
We have searched for axions which could have been produced in the solar core
using an axion helioscope with a 2.3m-long 4T superconducting magnet. Axion
mass region up to m_a=0.26eV was newly explored by introducing
dispersion-matching gas. Preliminary analysis sets a limit on axion-photon
coupling constant to be less than (6.4--9.6)e-10 GeV^{-1} (95%CL) for this mass
region from the absence of the axion signal. This is more stringent than the
limit inferred from the solar age consideration and also more stringent than
the recent helioseismological bound.Comment: 6 pages, 4 PostScript figures; submitted to Proceedings of IDM2000
(World Scientific
Surface-Active and Photochemical Properties of Sodium p
An ultraviolet (UV)-degradative anionic surfactant, sodium p-dodecylbenzylsulfate, was prepared and its surface-active and photochemical properties in water were examined. The surface activities such as solubilizing, foaming, and dispersing powers were as good as those of synthetic detergents, linear alkylbenzenesulfonate and sodium dodecylsulfate. Upon UV irradiation, the surfactant was degraded to give p-dodecylbenzyl alcohol, a nonsurfactant.ArticleJOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY. 33(6):812-815 (2012)journal articl
Four-body cluster structure of double- hypernuclei
Energy levels of the double- hypernuclei
He, Li,
Li, Li,
Be and Be are predicted on
the basis of the four-body model with He and , respectively.Comment: 27 pages (preprint style), 12figures submitted to Phys. Rev.
Quantum fluctuation and geometrical frustration effects on electric polarization
We examine theoretically a possibility of ferroelectricity caused by
electronic charge order without inversion symmetry, motivated by layered iron
oxides. Quantum electronic models in a paired-triangular lattice are analyzed
by utilizing the variational Monte Carlo simulation. Our calculation
demonstrates that combined effects of electron transfer between the layers,
corresponding to quantum fluctuation between the potential minima, and
geometrical frustration promote appearance of an electric polarization. Present
results are in contrast to the conventional manner of quantum fluctuation in
ferroelectricity.Comment: 5 pages, 4 figure
Baryon-baryon interactions in the SU6 quark model and their applications to light nuclear systems
Interactions between the octet-baryons (B8) in the spin-flavor SU6 quark
model are investigated in a unified coupled-channels framework of the
resonating-group method (RGM). The interaction Hamiltonian for quarks consists
of the phenomenological confinement potential, the color Fermi-Breit
interaction with explicit flavor-symmetry breaking (FSB), and effective-meson
exchange potentials of scalar-, pseudoscalar- and vector-meson types. The model
parameters are determined to reproduce the properties of the nucleon-nucleon
(NN) system and the low-energy cross section data for the hyperon-nucleon (YN)
interactions. The NN phase shifts and many observables for the NN and YN
interactions are nicely reproduced. Properties of these B8 B8 interactions are
analyzed through the G-matrix calculations. The B8 B8 interactions are then
applied to some of few-baryon systems and light Lambda-hypernuclei in a
three-cluster Faddeev formalism using two-cluster RGM kernels. An application
to the three-nucleon system shows that the quark-model NN interaction can give
a sufficient triton binding energy with little room for the three-nucleon
force. The hypertriton Faddeev calculation indicates that the attraction of the
Lambda N interaction in the 1S0 state is only slightly more attractive than
that in the 3S1 state. In the application to the alpha alpha Lambda system, the
energy spectrum of 9 Lambda Be is well reproduced using the alpha alpha RGM
kernel. The very small spin-orbit splitting of the 9 Lambda Be excited states
is also discussed. In the Lambda Lambda alpha Faddeev calculation, the NAGARA
event for 6 Lambda Lambda He is found to be consistent with the quark-model
Lambda Lambda interaction.Comment: 77 pages, 33 figures, review article to be published in Prog. Part.
Nucl. Phy
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