Purpose of the Research Project

(A) (Group-A01 and A02)

In order to investigate the high density region in the central part of the neutron stars, where strange quarks are expected to appear, we study strangeness nuclear systems (hypernuclei) and determine the hyperon-nucleon interactions to be used as an input for the EOS.

(B) (Group-B01, B02, and B03)

In order to understand low/medium density neutron matter in the outer region of
the neutron stars, we investigate properties of neutron-rich nuclear matter and
thin neutron matter through various studies of neutron-rich unstable nuclei.

We also investigate laser-cooled ultra-cold Fermi gas systems, of which
properties are similar to thin neutron matter in the crust of the neutron stars.

(C) (Group-C01)

Both of the mass and the radius of the neutron star would strongly restrict
and/or confirm the EOS. However, direct measurement of the radius has not been
achieved yet. Using X-ray observatory satellites such as ASTRO-H with new X-ray
detectors, we will obtain direct data on the radius for several samples.

(D) (Group-D01)

The theory group studies related subjects on nuclear/hadron physics, cold atomic
systems, and astronomical physics to analyze/interpret the results of (A), (B),
(C). From (A) and (B), the best EOS will be constructed, which will be then
confirmed by the radius data (C). Exotic neutron-star matter such as superfluid
and pasta-like matter will be also investigated.