Novel halos in light kaonic nuclei as an indicator of nuclear equation of state at supra-normal densities

Abstract

The sensitive correlations between the low-density halo structure and the high-density properties of the nuclear equation of state (EOS) are constructed in light kaonic nuclei with the relativistic mean-field theory. More specifically, the 1p 1/2 halo spreads out linearly with increasing the pressure and sound velocity square at supra-normal densities and decreasing the incompressibility at saturation density. These results suggest that the novel halo in light kaonic nuclei can serve as a sensitive indicator of the nuclear EOS of symmetric matter at supra-normal densities. The experimental production and detection of the light kaonic nuclei, yet to be available, is discussed in some details at last.

Level inversion in kaonic nuclei and the high-density nuclear equation of state

“…Due to the strong attraction between nucleons and K − mesons, the nucleon potential in kaonic nuclei is greatly changed by the implantation of the K − meson. We can see that the nucleon potential in kaonic nucleus 18 K − O is much deeper than that in normal nucleus 18 O in the core region (r < 2f m). Its direct consequence is that the nuclear density in the core of 18 K − O is over two times the saturation density, dramatically larger than that of 18 O.…”

“…We can see that the nucleon potential in kaonic nucleus 18 K − O is much deeper than that in normal nucleus 18 O in the core region (r < 2f m). Its direct consequence is that the nuclear density in the core of 18 K − O is over two times the saturation density, dramatically larger than that of 18 O. We notice that the implanted K − meson is almost squeezed in the core region where the huge variation in the nucleon potential takes place consistently, as seen in Fig.…”

“…Displayed in Fig. 1 are the nucleon potentials and nuclear densities in 18 O and 18 K − O. Due to the strong attraction between nucleons and K − mesons, the nucleon potential in kaonic nuclei is greatly changed by the implantation of the K − meson.…”

“…In kaonic nuclei, the binding of the antikaon is given by its additive couplings with scalar and vector mesons, whereas this is apart from the nucleonic binding in normal nuclei that is a cancellation of the scalar and vector potentials. Such a deep binding in kaonic nuclei results in correspondingly much deeper nucleonic potential due to the coupling between the antikaon and nucleons, giving rise to exotic features such as the dense core at supra-normal density [16,17] and diffusive halo [18]. Here, we adopt the RMF theory to investigate the ground-state properties of kaonic nuclei and its relationship with the nuclear EOS.…”

“…Compared with the data at high densities extracted from heavy-ion collisions, the structural properties in the ground state of kaonic nuclei should be more precise for probing the high-density EOS. In the past, we have actually made some efforts to establish the correlation between the low-density halo phenomenon in kaonic nuclei and the stiffness of EOS at saturation and high densities [18]. In this work, we further investigate the ground-state properties of kaonic nuclei in the framework of relativistic mean-field (RMF) theory.…”