Probing nuclear bubble configurations by proton-induced reactions

In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, a nuclear bubble configuration in the hypothetical ${}^{48}\mathrm{Si}$ nucleus is studied by a proton-induced central reaction at an incident beam energy of 0.8 GeV/nucleon. It is found that along the beam direction more energetic protons are emitted with a bubble configuration in the target. In the forward angles, compared with the case without a bubble configuration, less-scattered energetic protons are emitted with a bubble configuration in the target. We thus provide a new way to probe the bubble configuration in nuclei.

Figure 1

The density distributions of neutrons and protons in the ground state for ${}^{48}\mathrm{Si}$, calculated by the SHF and the PKA1 Lagrangian of the RHFB.

Figure 2

The sketch of the reaction with a proton as a projectile and ${}^{48}\mathrm{Si}$ as a target. The depth of color represents the denseness of baryonic density, namely, the density increases from low to high as the color changes from light blue to dark blue.

Figure 3

Counts of emitted protons as a function of kinetic energy detected in the beam direction in the central $p+{}^{48}\mathrm{Si}$ reaction at 0.8 GeV/nucleon with (RHFB + PKA1) and without a (SHF) bubble configuration in the target.

Figure 4

Counts of emitted protons as a function of scattering angle (relative to the beam direction) in the central $p+{}^{48}\mathrm{Si}$ reaction at 0.8 GeV/nucleon with and without a bubble configuration in the target. Different panels denote different kinetic-energy cuts.