Modification of hyperon masses in nuclear matter

We investigate the properties of baryons within the framework of the in-medium modified SU(3) Skyrme model. The modification is performed by a minimal way, the medium functionals in the SU(2) sector being introduced. These functionals are then related to nuclear matter properties near the saturation point. The modifications in the SU(3) sector are performed by changing additionally kaon properties in nuclear matter. The results show that the properties of baryons in the strange sector are sensitive to the in-medium modifications of the kaon properties. We discuss the consistency of the in-medium modifications of hadron properties in this approach, comparing the present results with those from other models.

Figure 1

The density dependence of the input parameters that are defined in Eq. (43). The results shown are those normalized relatively to their values in free space.

Figure 2

The ratio of functionals to their free space values as functions of $\rho /{\rho }_0$: (a) $E_0^{*}/E_0$ (solid curve) and ${\mathrm{\Omega }}^{*}/\mathrm{\Omega }$ (dashed curve) are independent of the kaon properties; (b) $c^{*}/c$ and ${\omega }_{-}^{*}/{\omega }_{-}$ are dependent on the kaon properties. In the figure (b), the solid and dashed curves correspond to the results of $c^{*}/c$ and ${\omega }_{-}^{*}/{\omega }_{-}$ with $C=0.2$, whereas the dotted and dot-dashed ones illustrate those of $c^{*}/c$ and ${\omega }_{-}^{*}/{\omega }_{-}$ with $C=0$, respectively.

Figure 3

The density dependence of the mass splittings of the baryon octet, $m_{\mathrm{\Lambda }}^{*}-m_N^{*},m_{\mathrm{\Sigma }}^{*}-m_{\mathrm{\Lambda }}^{*}$, and $m_{\mathrm{\Xi }}^{*}-m_{\mathrm{\Sigma }}^{*}$, are illustrated by the solid, dotted, and dashed curves, respectively. The figure (a) corresponds to $C=0$ and (b) corresponds to $C=0.2$, respectively.

Figure 4

The density dependence of the mass splittings of the baryon decuplet, $m_{{\mathrm{\Sigma }}^{*}}^{*}-m_{\mathrm{\Delta }}^{*},m_{{\mathrm{\Xi }}^{*}}^{*}-m_{{\mathrm{\Sigma }}^{*}}^{*}$, and $m_{\mathrm{\Omega }}^{*}-m_{{\mathrm{\Xi }}^{*}}^{*}$, are illustrated by the solid, dotted, and dashed curves, respectively. Figure (a) corresponds to $C=0$ and (b) corresponds to $C=0.2$, respectively.