8–13 Sept 2025
Integrated Innovation Building (IIB), RIKEN Kobe Campus
Asia/Tokyo timezone
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Constraints on the nuclear equation of state from astrophysical observations using relativistic mean-field models

9 Sept 2025, 15:00
20m
Auditorium (8F) (Integrated Innovation Building (IIB), RIKEN Kobe Campus)

Auditorium (8F)

Integrated Innovation Building (IIB), RIKEN Kobe Campus

Minatojima-minamimachi 6-7-1, Kobe, Japan
3. Microscopic calculations of neutron-rich dense nuclear matter NuSym Scientific Session

Speaker

Tsuyoshi Miyatsu (Soongsil University)

Description

Taking into account astrophysical observations of neutron stars, we present new effective interactions based on relativistic mean-field (RMF) models. In addition to the isovector-vector ($\vec{\rho}^{\,\mu}$) meson, the isovector-scalar ($\vec{\delta}$) meson and meson-mixing terms involving isoscalar and isovector mesons---specifically $\sigma^{2}\vec{\delta}^{2}$ and $\omega_{\mu}\omega^{\mu}\vec{\rho}_{\nu}\cdot\vec{\rho}^{\,\nu}$---are incorporated into conventional RMF models to investigate the properties of isospin-symmetric nuclear matter. The equations of states (EoSs) for neutron stars are constructed to satisfy precise measurements of neutron-star radii from the NICER mission, as well as the stringent constraint on tidal deformability from the binary neutron-star merger event GW170817. Our results show that recent neutron-star observations significantly affect the construction of nuclear EoSs, leading to a softening of the nuclear symmetry energy around twice the nuclear saturation density, primarily due to $\sigma$-$\delta$ mixing.
We also discuss properties of finite nuclei with a focus on the neutron skin thickness of $^{48}$Ca and $^{208}$Pb, in light of data from CREX and PREX2 experiments.

Presentation Style Oral Presentation

Author

Tsuyoshi Miyatsu (Soongsil University)

Co-authors

Myung-Ki CHEOUN (Soongsil University) Prof. Kyungsik Kim (Korea Aerospace University) Prof. Koichi Saito (Tokyo University of Science)

Presentation materials