1,902 research outputs found
Developing Cloud Chambers with High School Students
The result and outcome of the \textit{cloud chamber project}, which aims to
develop a cloud chamber useful for science education is reported in detail. A
project includes both three high school students and a teacher as a part of
Super Science High School (SSH) program in our school. We develop a
dry-ice-free cloud chamber using salt and ice (or snow). Technical details of
the chamber are described. We also argue how the project have affected
student's cognition, motivation, academic skills and behavior. The research
project has taken steps of professional researchers, i.e., in planning
research, applying fund, writing a paper and giving a talk in conferences. From
interviews with students, we have learnt that such style of scientific activity
is very effective in promoting student's motivation for learning science.Comment: 9 pages, accepted to the proceedings of APPC12 - the 12th Asia
Pacific Physics Conferenc
Modern Dynamical Coupled-Channels Calculations for Extracting and Understanding the Nucleon Spectrum
We give an overview of recent progress in the spectroscopic study of nucleon
resonances within the dynamical coupled-channels analysis of meson-production
reactions. The important role of multichannel reaction dynamics in
understanding various properties of nucleon resonances is emphasized.Comment: 11 pages, 8 figures. Plenary talk at The 14th International
Conference on Meson-Nucleon Physics and the Structure of the Nucleon
(MENU2016), Kyoto, Japan, July 25-30, 201
Negative Parity Baryons in the QCD Sum Rule
Masses and couplings of the negative parity excited baryons are studied in
the QCD sum rule. Separation of the negative-parity spectrum is proposed and is
applied to the flavor octet and singlet baryons. We find that the quark
condensate is responsible for the mass splitting of the ground and the
negative-parity excited states. This is expected from the chiral symmetry and
supports the idea that the negative-parity baryon forms a parity doublet with
the ground state. The meson-baryon coupling constants are also computed for the
excited states in the QCD sum rule. It is found that the \pi NN^* coupling
vanishes in the chiral limit.Comment: 13pp, LaTeX, 1 EPS figure, uses epsf.sty, Talk given by M.O. at
CEBAF/INT workshop "N* physics", Seattle, September (1996), to appear in the
proceeding
Chiral symmetry aspects of positive and negative parity baryons
Chiral symmetry aspects for baryon properties are studied. After a brief
discussion on general framework, we introduce two distinctive chiral group
representations for baryons: the naive and mirror assignments. Using linear
sigma models, nucleon properties are studied in both representations. Finally,
we propose an experiment to distinguish the two assignments in the reactions of
pion and eta productions.Comment: PTPTeX 12 pages, Proceedings for the YITP-RCNP workshop Chiral
Restoration in Nuclear Medium, Kyoto, October 200
Determination of the axial coupling constant in the linear representations of chiral symmetry
If a baryon field belongs to a certain linear representation of chiral
symmetry of , the axial coupling constant can be
determined algebraically from the commutation relations derived from the
superconvergence property of pion-nucleon scattering amplitudes. This
establishes an algebraic explanation for the values of of such as the
non-relativistic quark model, large- limit and the mirror assignment for
two chiral partner nucleons. For the mirror assignment, the axial charges of
the positive and negative parity nucleons have opposite signs. Experiments of
eta and pion productions are proposed in which the sign difference of the axial
charges can be observed.Comment: 7 pages, proceedings for EMI int. conf. at RCNP, Dec. 200
Relation between the separable and one-boson-exchange potential for the covariant Bethe-Salpeter equation
We investigate the relation between the rank I separable potential for the
covariant Bethe-Salpeter equation and the one-boson-exchange potential. After
several trials of the parameter choices, it turns out that it is not always
possible to reproduce the phase-shifts calculated from a single term of the
one-boson-exchange potential especially of the -exchange term,
separately by the rank I separable potential. Instead, it is shown that the
separable potential is useful to parameterize the total nucleon-nucleon
interaction.Comment: 10 pages, 8 figures, to appear in J.Phys.
Nuclear G-Matrix Elements from Nonlocal Potentials
We study effects of nonlocality in the nuclear force on the G-matrix elements
for finite nuclei. Nuclear G-matrix elements for \O16 are calculated in the
harmonic oscillator basis from a nonlocal potential which models quark exchange
effects between two nucleons. We employ a simple form of potential that gives
the same phase shifts as a realistic local nucleon potential. The G-matrix
elements calculated from the nonlocal potential show moderate increase in
repulsion from those derived from the local potential.Comment: 11 page, LaTeX, 2 PS figures, uses epsf.st
Determining the quantum numbers through a Kaon induced reaction
We study the reaction with kinematical condition suited to
the production of the resonance. It is shown that in this reaction
with the polarization experiment, a combined consideration of the strength at
the peak and the angular dependence of cross section can help determine the
quantum numbers.Comment: 4 pages, 3 figures, Talk given at International Workshop PENTAQUARK04
at SPring-8, Japan, July 20-23, 200
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