The ground state properties of the spherical nucleus ^40Ca have been investigated by using constrained spherical Hartree Fock （CSHF） approximation at equilibrium and under high radial compression in a six major shel...The ground state properties of the spherical nucleus ^40Ca have been investigated by using constrained spherical Hartree Fock （CSHF） approximation at equilibrium and under high radial compression in a six major shells. The effective baryon-baryon interaction that includes the △（1236） resonance freedom degrees to calculate nuclear properties is used. The nucleon-nucleon （N-N） interaction is based on Reid soft core （RSC） potential. The results of calculations show that much of increase in the nuclear energy generated under compression is used to create the massive △ particles. The number of △ ＇s can be increased to about 2.1% of constituents of nucleus when nuclear density reaches about 1.34 times of normal density. The single particle energy levels are calculated and their behavior under compression is also examined. △ good agreement has been found between current calculations and phenomenological shell model for low lying single-particle spectra. The gap between shells is very clear and L-S coupling become stronger as increasing the static load on the nucleus. The results show a considerable reduction in compressibility when freedom degrees of △＇s are taken into account. It has been found that the total nuclear radial density becomes denser in the interior and less dense in the exterior region of nucleus. The surface of nucleus becomes more and more responsive to compression than outer region.展开更多
With an oscillator basis,the nuclear Hamiltonian is defined in a no-core model space.It consists of an effective nucleon-nucleon interaction obtained with Brueckner theory from the Reid soft core interaction,a Coulomb...With an oscillator basis,the nuclear Hamiltonian is defined in a no-core model space.It consists of an effective nucleon-nucleon interaction obtained with Brueckner theory from the Reid soft core interaction,a Coulomb potential,nucleon-delta transition potentials,and delta-delta interaction terms.By performing spherical Hartree-Fock(SHF) calculations with the realistic baryon Hamiltonian,the ground state properties of 40Ca are studied.For an estimate of how the delta degree of freedom is excited,SHF calculations are performed with a radial constraint to compress the nucleus.The delta degree of freedom is gradually populated as the nucleus is compressed.The number of Δ's is decreased by increasing model space.Large amount of the compressive energy is delivered to create massive Δ in the nucleus.There is a significant reduction in the static compression modulus for RSC static compressions which is reduced by including the Δ excitations.The static compression modulus is decreased significantly by en larging the nucleon model space.The results suggest that inclusion of the delta in the nuclear dynamics could head to a significant softening of the nuclear equation of state.展开更多
文摘The ground state properties of the spherical nucleus ^40Ca have been investigated by using constrained spherical Hartree Fock （CSHF） approximation at equilibrium and under high radial compression in a six major shells. The effective baryon-baryon interaction that includes the △（1236） resonance freedom degrees to calculate nuclear properties is used. The nucleon-nucleon （N-N） interaction is based on Reid soft core （RSC） potential. The results of calculations show that much of increase in the nuclear energy generated under compression is used to create the massive △ particles. The number of △ ＇s can be increased to about 2.1% of constituents of nucleus when nuclear density reaches about 1.34 times of normal density. The single particle energy levels are calculated and their behavior under compression is also examined. △ good agreement has been found between current calculations and phenomenological shell model for low lying single-particle spectra. The gap between shells is very clear and L-S coupling become stronger as increasing the static load on the nucleus. The results show a considerable reduction in compressibility when freedom degrees of △＇s are taken into account. It has been found that the total nuclear radial density becomes denser in the interior and less dense in the exterior region of nucleus. The surface of nucleus becomes more and more responsive to compression than outer region.
文摘With an oscillator basis,the nuclear Hamiltonian is defined in a no-core model space.It consists of an effective nucleon-nucleon interaction obtained with Brueckner theory from the Reid soft core interaction,a Coulomb potential,nucleon-delta transition potentials,and delta-delta interaction terms.By performing spherical Hartree-Fock(SHF) calculations with the realistic baryon Hamiltonian,the ground state properties of 40Ca are studied.For an estimate of how the delta degree of freedom is excited,SHF calculations are performed with a radial constraint to compress the nucleus.The delta degree of freedom is gradually populated as the nucleus is compressed.The number of Δ's is decreased by increasing model space.Large amount of the compressive energy is delivered to create massive Δ in the nucleus.There is a significant reduction in the static compression modulus for RSC static compressions which is reduced by including the Δ excitations.The static compression modulus is decreased significantly by en larging the nucleon model space.The results suggest that inclusion of the delta in the nuclear dynamics could head to a significant softening of the nuclear equation of state.
