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Chiral Sigma Model with Pion Mean Field in Finite Nuclei
The properties of infinite matter and finite nuclei are studied by using the
chiral sigma model in the framework of the relativistic mean field theory. We
reconstruct an extended chiral sigma model in which the omega meson mass is
generated dynamically by the sigma condensation in the vacuum in the same way
as the nucleon mass. All the parameters of chiral sigma model are essentially
fixed from the hadron properties in the free space. In nuclear matter, the
saturation property comes out right, but the incompressibility is too large and
the scalar and vector potentials are about a half of the phenomenological ones,
respectively. This fact is reflected to the properties of finite nuclei. We
calculate N = Z even-even mass nuclei between N = 16 and N = 34. The extended
chiral sigma model without the pion mean field leads to the result that the
magic number appears at N = 18 instead of N = 20 and the magic number does not
appear at N = 28 due to the above mentioned nuclear matter properties. The
latter problem, however, could be removed by the introduction of the finite
pion mean field with the appearance of the magic number at N = 28. We find that
the energy differences between the spin-orbit partners are reproduced by the
finite pion mean field which is completely a different mechanism from the
standard spin-orbit interaction.Comment: 19 pages, 9 figures. Prog. Theor. Phys. to be publishe
Reduced hierarchy equations of motion approach with Drude plus Brownian spectral distribution: Probing electron transfer processes by means of two- dimensionalcorrelation spectroscopy
We theoretically investigate an electron transfer (ET) process in a
dissipative environment by means of two-dimensional (2D) correlation
spectroscopy. We extend the reduced hierarchy equations of motion approach to
include both overdamped Drude and underdamped Brownian modes. While the
overdamped mode describes the inhomogeneity of a system in the slow modulation
limit, the underdamped mode expresses the primary vibrational mode coupled with
the electronic states. We outline a procedure for calculating 2D correlation
spectrum that incorporates the ET processes. The present approach has the
capability of dealing with system-bath coherence under an external
perturbation, which is important to calculate nonlinear response functions for
non-Markovian noise. The calculated 2D spectrum exhibits the effects of the ET
processes through the presence of ET transition peaks along the
axis, as well as the decay of echo signals.Comment: 28 pages, 8 figures; J. Chem. Phys. 137 (2012
A competing order scenario of two-gap behavior in hole doped cuprates
Angle-dependent studies of the gap function provide evidence for the
coexistence of two distinct gaps in hole doped cuprates, where the gap near the
nodal direction scales with the superconducting transition temperature ,
while that in the antinodal direction scales with the pseudogap temperature. We
present model calculations which show that most of the characteristic features
observed in the recent angle-resolved photoemission spectroscopy (ARPES) as
well as scanning tunneling microscopy (STM) two-gap studies are consistent with
a scenario in which the pseudogap has a non-superconducting origin in a
competing phase. Our analysis indicates that, near optimal doping,
superconductivity can quench the competing order at low temperatures, and that
some of the key differences observed between the STM and ARPES results can give
insight into the superlattice symmetry of the competing order.Comment: 9 pages, 7 fig
An approach toward the successful supernova explosion by physics of unstable nuclei
We study the explosion mechanism of collapse-driven supernovae by numerical
simulations with a new nuclear EOS based on unstable nuclei. We report new
results of simulations of general relativistic hydrodynamics together with the
Boltzmann neutrino-transport in spherical symmetry. We adopt the new data set
of relativistic EOS and the conventional set of EOS (Lattimer-Swesty EOS) to
examine the influence on dynamics of core-collapse, bounce and shock
propagation. We follow the behavior of stalled shock more than 500 ms after the
bounce and compare the evolutions of supernova core.Comment: 4 pages, 2 figures, contribution to Nuclei in the Cosmos 8, to appear
in Nucl. Phys.
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