arXiv subjects

Yoshitaka Iwasaki

Publications and source records attributed to Yoshitaka Iwasaki.

3 recordsLinked to original sources

arXiv2000

A relation among the effective nucleon mass, the incompressibility and the effective $σ$-meson mass in nuclear matter

A relation among the effective nucleon mass $M^*$, the incompressibility $K$ and the effective $σ$-meson mass $m_{\rm s}^*$ in nuclear matter is studied by using the relativistic nuclear model. We found that there is a strong correlation between $M^*$ and $m_{\rm s}^*$, while there is only a weak correlation between $K$ and $m_{\rm s}^*$. At the normal density, $m_{\rm s}^*$ is smaller than the one at zero density, if $M^*$ is smaller than 0.8 times of the nucleon mass at zero density. It is also found that the off-shell effective mass $μ_{\rm s}^*$ is related directly to $K$ and $M^*$ at the normal density.

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arXiv1997

Meson-nucleon vertex corrections to the vacuum polarization in the cutoff field theory and tensor coupling

At zero-density, meson-nucleon vertex corrections to vacuum polarization are studied in the $σ-ω$ model with the cutoff. It is shown that the properties of the vertex corrections to vacuum polarization are somewhat different from those described by the ordinary renormalization procedures when the cutoff is small (< 5 GeV). The low-energy effective Lagrangian is constructed in the framework of the renormalization group method. The weak tensor and derivative couplings of meson-nucleon interactions may be needed in the low-energy effective theory of mesons and nucleons.

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arXiv1997

Vacuum Effects and Compressional Properties of Nuclear Matter in Cutoff Field Theory

Including the vacuum effects, the compressional properties of nuclear matter are studied in the cutoff field theory. Under the Hartree approximation, the low-energy effective Lagrangian is derived in the framework of the renormalization group methods. The coefficients are determined in a way where the physical results hardly depend on the value of the cutoff which is conveniently introduced into the theory. It is shown that, to reproduce the empirical data of the nucleus incompressibility, the compressibility of the nuclear matter is favorable to be 250$\sim$350MeV.

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