301 research outputs found
Effective Kbar N interaction based on chiral SU(3) dynamics
The effective Kbar N interaction based on chiral SU(3) coupled-channel
dynamics is derived and its extrapolation below the Kbar N threshold is studied
in detail. Starting from the coupled-channel scattering equations, we eliminate
the channels other than Kbar N and obtain an effective interaction in the
single Kbar N channel. An equivalent local potential in coordinate space is
constructed such as to reproduce the full scattering amplitude of the chiral
SU(3) coupled-channel framework. We discuss several realistic chiral
SU(3)-based models in comparison to reach conclusions about the uncertainties
involved. It turns out that, in the region relevant to the discussion of deeply
bound Kbar-nuclear few-body systems, the resulting energy-dependent, equivalent
local potential is substantially less attractive than the one suggested in
previous purely phenomenological treatments.Comment: RevTeX4, 16 pages, 15 figures, 5 tables, effect of higher order terms
is discussed, final version to appear in Phys. Rev.
Structures and Transitions in Light Unstable Nuclei
We study the structures of the unstable Be isotopes with the theoretical
method of antisymmetrized molecular dynamics. It is found that various
structures of the excited states appear in the low-energy region of
neutron-rich Be nuclei. Focusing on the 2 clustering, we analyze the
intrinsic structures with the help of the experimental data of Gamow-Teller
transitions.Comment: 8 pages and 4 figure
Kaonic hydrogen and K^- p scattering
Chiral SU(3) effective field theory in combination with a relativistic
coupled channels approach is used to perform a novel analysis of the strong
interaction shift and width in kaonic hydrogen in view of the new accurate DEAR
measurements. Questions of consistency with previous K^- p data are examined.
Coulomb and isospin breaking effects turn out to be important and are both
taken into account in this work.Comment: 4 pages, 4 figure
A narrow quasi-bound state
The energies and widths of quasi-bound states with isospin I=1/2 are
evaluated in two methods, the fixed center approximation to the Faddeev
equation and the variational method approach to the effective one-channel
Hamiltonian. The interactions are constructed so that they dynamically
generate the (I=0, ) resonance state. We find
that the system is bound by about 250 MeV from the threshold, MeV. Its width including both the mesonic decay and the
absorption, is estimated to be about 20-40 MeV. The I=0 pair in the
system is found to form a cluster that is similar to the .Comment: 17 pages, 18 figures, 3 table
Narrow Bound States of the DNN System
We report on a recent calculation of the properties of the DNN system, a charmed meson with two nucleons. The system is analogous to the system substituting a strange quark by a charm quark. Two different methods are used to evaluate the binding and width, the Fixed Center approximation to the Faddeev equations and a variational calculation. In both methods we find that the system is bound by about 200 MeV and the width is smaller than 40 MeV, a situation opposite to the one of the system and which makes this state well suited for experimental observation
Signature of strange dibaryon in kaon-induced reaction
We examine how the signature of the strange-dibaryon resonances in the
barKNN-piSigmaN system shows up in the scattering amplitude on the physical
real energy axis within the framework of Alt-Grassberger-Sandhas (AGS)
equations. The so-called point method is applied to handle the three-body
unitarity cut in the amplitudes. We also discuss the possibility that the
strange-dibaryon production reactions can be used for discriminating between
existing models of the two-body barKN-piSigma system with Lambda(1405).Comment: 4 pages, 6 figures, talk given at The Fifth Asia-Pacific Conference
on Few-Body Problems in Physics 2011 (APFB2011), held in Seoul, Korea, August
22-26, 201
The (K-,p) reaction on nuclei with in-flight kaons
We perform a theoretical study of the spectrum of protons with kinetic
energies of around 600 MeV, emitted following the interaction of 1 GeV/c kaons
with nuclei. A recent experimental analysis of this (K-,p) reaction on 12C,
based on the dominant quasielastic process, has suggested a deeply attractive
kaon nucleus potential. Our Monte Carlo simulation considers, in addition, the
one-and two-nucleon K- absorption processes producing hyperons that decay into
\pi N pairs. We find that this kaon in-flight reaction is not well suited to
determine the kaon optical potential due, essentially, to the limited
sensitivity of the cross section to its strength, but also to unavoidable
uncertainties from the coincidence requirement applied in the experiment. A
shallow kaon nucleus optical potential obtained in chiral models is perfectly
compatible with the observed spectrum.Comment: To appear in the proceedings of the 10th International Conference on
Hypernuclear and Strange Particle Physics, Tokai, Ibaraki (Japan), 14-18
September, 200
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