93 research outputs found
Kaonic nuclei studied based on a new framework of Antisymmetric Molecular Dynamics
We have developed a new framework of Antisymmetrized Molecular Dynamics
(AMD), to adequately treat the I=0 \={K}N interaction, which is essential to
study kaonic nuclei. The improved points are 1) pK/n\={K} mixing and 2)
total spin and isospin projections. These improvements enable us to investigate
various kaonic nuclei (ppnK, pppK, pppnK, BeK and
BK) systematically. We have found that they are deeply bound and
extremely dense with a variety of shapes.Comment: 10 pages, 5 figure
High-density \={K} nuclear systems with isovector deformation
Using a phenomenological \={K}N potential which reproduces (1405) as
an I=0 bound state of \={K}N, we investigated deeply bound kaonic nuclei,
ppnK and BeK, with the method of Antisymmetrized Molecular
Dynamics. Our calculations show that strongly bound kaonic nuclear systems with
unusual exotic structures are formed around the K, which attracts the
surrounding nucleons to an extremely high-density assembly and induces a
proton-neutron separation, ``isovector deformation''.Comment: 4 pages, 11 figures, submitted to Phys. Rev. Let
Comprehensive application of a coupled-channel complex scaling method to the KbarN-piY system
We have applied the coupled-channel complex scaling method (ccCSM) to
K^{bar}N-\pi Y system. One advantage of ccCSM is that resonant states as well
as scattering states can be treated in the same framework. For the interactions
in the system, we have constructed a meson-baryon potential-matrix by basing on
the chiral SU(3) theory and respecting the K^{bar}N scattering length obtained
in the Martin's analysis. For future purpose to apply it more complicated
system such as K^{bar}NN, we adopt a local Gaussian form in the r-space. We
have investigated both the non-relativistic (NR) and the semi-relativistic (SR)
kinematics. In the SR case, two types of the potentials are obtained. To test
the constructed potentials, we have calculated scattering amplitudes and
searched resonances. One resonance pole, corresponding to \Lambda(1405), is
found in isospin I=0 system around (1419, -20) MeV ((1425, -25) or (1419, -13)
MeV) on complex-energy plane with the NR (SR) kinematics. Mean distance between
meson and baryon in the resonant state is 1.3 - i0.3 fm (1.2 - i0.5 fm) for NR
(SR), in which the states are treated as Gamow states. In addition, we have
observed a signature of another pole in lower-energy region involving large
decay width, although they are unstable against the change of scaling angle
\theta. This may correspond to the lower pole of the double-pole of
\Lambda(1405) discussed in literature to date.Comment: 51 pages, 17 figures, to appear in Nuclear Physics
Fully coupled-channel study of resonance in a chiral SU(3)-based potential
We have investigated the most essential kaonic nucleus "" as a
resonant state of the -- coupled channel
system using a chiral SU(3)-based potential. We treat the ""
resonance adequately with a fully coupled-channel complex scaling method (full
ccCSM). Self-consistency needs to be considered for the energy dependence of
the chiral SU(3)-based potential. In the present study, we propose a simple
prescription for the treatment of self-consistency, considering the {\it
averaged threshold} and {\it averaged binding energy of mesons}. With this
prescription, we have successfully found the self-consistent solutions of the
"" three-body resonance. The results indicate that the "" system
is bound rather shallowly. In particular, when the potential parameters are
constrained with the latest scattering length, the binding energy
and half of the mesonic decay width are obtained as MeV and MeV,
respectively.Comment: 7 pages, 2 figures, accepted by Phys. Lett.
Strange tribaryons as Kbar-mediated dense nuclear systems
We discuss the implications of recently discovered strange tribaryons in
4He(stopped-K-, p)S0 (3115) and 4He(stopped-K, n) S1 (3140) within the
framework of deeply bound kbar states formed on shrunk nuclear cores. S1 (3140)
corresponds to T=0 ppnK-, whereas S0 (3115) to T=1 pnnK-, which is an isobaric
analog state of pppK-, predicted previously. The observed binding energies can
be accounted for by including the relativistic effect and by invoking a
medium-enhanced kbar-N interaction by 15%. We propose various experimental
methods to further study these and related bound systems.Comment: 8 pages, 6 figure
Modification of triaxial deformation and change of spectrum in $^{25}_{\ \Lambda}\Lambda$ hyperon
The positive-parity states of Mg with a hyperon
in orbit were studied with the antisymmetrized molecular dynamics for
hypernuclei. We discuss two bands of Mg corresponding to the
and bands of Mg. It is found that the energy of the
band is shifted up by about 200 keV compared to
Mg. This is because the hyperon in orbit reduces the
quadrupole deformation of the band, while it
does not change the deformation of the band
significantly.Comment: 19 pages, 3 figure
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