35,996 research outputs found
QCD color interactions between two quarks
We study the QCD color interactions between static two heavy quarks at zero
temperature in a quenched SU(3) lattice gauge simulation: in addition to the
standard singlet potentials, we calculate octet
potentials, symmetric and antisymmetric potentials. It is shown that the
antisymmetric channel behaves as a linearly rising potential at large
quark separations. We further find that the octet and symmetric
channels have the complex dependence on the distance; at short distances they
are repulsive forces, while at large distances, they show linearly rising
feature. Ratio of string tensions between singlet and
antisymmetric potentials is described in terms of the Casimir factor
Hyperons in nuclear matter
The chiral version of the QMC model, in which the effect of gluon and pion
exchanges is included self-consistently, is applied to the hyperons in a
nuclear medium. The hyperfine interaction due to the gluon exchange plays an
important role in the in-medium baryon spectra, while the pion-cloud effect is
relatively small. At the quark mean-field level, the feels more
attractive force than the \Sigma or \Xi in matter.Comment: 9 pages, 6 figure
Seismic Risk Evaluation of R.C. Buildings in Japan Designated in Accordance with the 1990 AIJ Guidelines
National Science Foundation Grant BCS 91-06390Kajima Foundatio
Disturbances of both cometary and Earth's magnetospheres excited by single solar flares
In the solar wind a comet plays the role of a windvane that moves three-dimensionally in the heliomagnetosphere. Among the solar systems bodies, only comets have a wide range of inclination angles of their orbital planes to the ecliptic plane ranging from 0 to 90 deg. Therefore, observations of cometary plasma tails are useful in probing the heliomagnetospheric conditions in the high heliolatitudinal region. A comet can be compared to a polar-orbiting probe encircling the Sun. We will introduce two rare cases in which the magnetospheres of both the comet and the Earth are disturbed by a single solar flare
The energy dependence of the amplitude and the three-nucleon interaction
By calculating the contribution of the three-body force to the
three-nucleon binding energy in terms of the amplitude using
perturbation theory, we are able to determine the importance of the energy
dependence and the contribution of the different partial waves of the
amplitude to the three-nucleon force. A separable representation of the
non-pole amplitude allows us to write the three-nucleon force in terms
of the amplitude for , propagation of the system,
and the amplitude for , with being the
quasi-particle amplitude in a given state. The division of the
amplitude into a pole and non-pole gives a procedure for the determination of
the form factor within the model. The total contribution of the
three-body force to the binding energy of the triton for the separable
approximation to the Paris nucleon-nucleon potential (PEST) is found to be very
small mainly as a result of the energy dependence of the amplitude, the
cancellation between the - and -wave amplitudes, and the soft
form factor.Comment: RevTex file, 36 pages, 10 figures available from authors:
[email protected]
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