arXiv subjects

Kunito Tuchitani

Publications and source records attributed to Kunito Tuchitani.

4 recordsLinked to original sources

arXiv2004

Effective hadron masses and effective interactions in nuclear matter

Relations among the effective hadron masses and the effective interactions in nuclear matter are studied by using the generalized relativistic mean field theory. We found that we can make the effective omega-meson mass smaller and the equation of state softer if we require that the omega-meson mean field is proportional to the baryon density. In this case, there is a simple and exact relation between the effective omega-meson mass and the effective omega-nucleon coupling. Because of this relation, the effective omega-nucleon coupling automatically decreases if the effective omega-meson mass decreases. Consequently, the equation of state becomes softer. A trial to embed the QCD sum-rule results into the hadron field theory is also shown.

nucl-th↗

arXiv2004

Effective meson masses, effective meson-nucleon couplings and neutron star radii

Using the generalized mean field theory, we have studied the relation among the effective meson masses, the effective meson-nucleon couplings and the equation of state (EOS) in asymmetric nuclear matter. If the effective omega-meson mass becomes smaller at high density, the EOS becomes stiffer. However, if we require that the omega-meson mean field is proportional to the baryon density, the effective omega-nucleon coupling automatically becomes smaller at the same time as the effective omega-meson mass becomes smaller. Consequently, the EOS becomes softer. A similar relation is found for the effective rho-meson mass and the effective rho-nucleon coupling. We have also studied the relation among the effective meson masses, the effective meson-nucleon couplings and a radius R of a neutron star. The R depends somewhat on the value of the effective omega-meson mass and the effective omega-nucleon coupling.

nucl-th↗

arXiv2001

Effective hadron masses and couplings in nuclear matter and incompressibility

The role of effective hadron masses and effective couplings in nuclear matter is studied using a generalized effective Lagrangian for sigma-omega model. A simple relation among the effective masses, the effective couplings and the incompressibility K is derived. Using the relation, it is found that the effective repulsive and the effective attractive forces are almost canceled to each other at the normal density. Inversely, if this cancellation is almost complete, K should be 250-350MeV.

nucl-th↗

arXiv1999

Nonlinear effects in Schwinger-Dyson Equation

We study nonlinear effects in the QED ladder Schwinger-Dyson(SD) equation. Without further approximations, we show that all nonlinear effects in the ladder SD equation can be included in the effective couplings and how a linear approximation works well. The analyses is generalized in the case of the improved ladder calculation with the Higashijima-Miransky approximation.

hep-ph↗