109,290 research outputs found
N K Pi molecular state with I=1 and J(Pi)=3/2-
The structure of the molecule-like state of with spin-parity
and isospin I=1 is studied within the chiral SU(3) quark
model. First we calculate the , , and phase shifts in the
framework of the resonating group method (RGM), and a qualitative agreement
with the experimental data is obtained. Then we perform a rough estimation for
the energy of , and the effect of the mixing to
the configuration is also considered. The
calculated energy is very close to the threshold of the system. A
detailed investigation is worth doing in the further study.Comment: 11 pages, 3 figures; accepted for publication in Phys. Rev.
Resonating group method study of kaon-nucleon elastic scattering in the chiral SU(3) quark model
The chiral SU(3) quark model is extended to include an antiquark in order to
study the kaon-nucleon system. The model input parameters , ,
are taken to be the same as in our previous work which focused on the
nucleon-nucleon and nucleon-hyperon interactions. The mass of the scalar meson
is chosen to be 675 MeV and the mixing of and is
considered. Using this model the kaon-nucleon and partial waves phase
shifts of isospin I=0 and I=1 have been studied by solving a resonating group
method (RGM) equation. The numerical results of , , ,
, and partial waves are in good agreement with the
experimental data while the phase shifts of partial wave are a little
bit too repulsive when the laboratory momentum of the kaon meson is greater
than 500 MeV in this present calculation.Comment: 17 pages, 6 figures. Final version for publicatio
Baryon-meson interactions in chiral quark model
Using the resonating group method (RGM), we dynamically study the
baryon-meson interactions in chiral quark model. Some interesting results are
obtained: (1) The Sigma K state has an attractive interaction, which
consequently results in a Sigma K quasibound state. When the channel coupling
of Sigma K and Lambda K is considered, a sharp resonance appears between the
thresholds of these two channels. (2) The interaction of Delta K state with
isospin I=1 is attractive, which can make for a Delta K quasibound state. (3)
When the coupling to the Lambda K* channel is considered, the N phi is found to
be a quasibound state in the extended chiral SU(3) quark model with several MeV
binding energy. (4) The calculated S-, P-, D-, and F-wave KN phase shifts
achieve a considerable improvement in not only the signs but also the
magnitudes in comparison with other's previous quark model study.Comment: 5 pages, 2 figures. Talk given at 3rd Asia Pacific Conference on
Few-Body Problems in Physics (APFB05), Korat, Nakhon Ratchasima, Thailand,
26-30 Jul 200
S, P, D, F wave KN phase shifts in the chiral SU(3) quark model
The , , , wave phase shifts have been studied in the chiral
SU(3) quark model by solving a resonating group method equation. The numerical
results of different partial waves are in agreement with the experimental data
except for the cases of and , which are less well described
when the laboratory momentum of the kaon meson is greater than 400 MeV.Comment: Prepared for 10th International Symposium on Meson-Nucleon Physics
and the Structure of the Nucleon (MENU 2004), Beijing, China, 29 Aug - 4 Sep
200
A Three-Pole Substrate Integrated Waveguide Bandpass Filter Using New Coupling Scheme
A novel three-pole substrate integrated waveguide (SIW) bandpass filter (BPF) using new coupling scheme is proposed in this paper. Two high order degenerate modes (TE102 and TE201) of a square SIW cavity and a dominant mode (TE101) of a rectangular SIW cavity are coupled to form a three-pole SIW BPF. The coupling scheme of the structure is given and analyzed. Due to the coupling between two cavities, as well as the coupling between source and load, three transmission zeros are created in the stopband of the filter. The proposed three-pole SIW BPF is designed and fabricated. Good agreement between simulated and measured results verifies the validity of the design methodology well
Preparation and characterization of interpenetrating phased TCP/HA/PLGA composites
The purpose of this study was to fabricate composites consisting of three interpenetrating networks: tricalcium phosphate (TCP), hydroxyapatite (HA), and poly(DL-lactide-co-glycolide) (PLGA). The porous TCP network was first produced by coating a polyurethane (PU) foam with hydrolysable alpha-TCP slurry. The HA network was derived from a calcium phosphate cement (CPC) filled in the porous TCP network. The remaining open pore network in the HA/TCP composite was further infiltrated with a PLGA network. The three sets of spatially continuous networks would have different biodegradation rates and thus bone tissue would grow towards the fastest biodegrading network while the remaining networks still maintaining their geometrical shape and carrying the physiological load for the tissue ingrowth
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