Delta Excitation in Compressed NeutronRich Double Magic Spherical Finite Nucleus 132 Sn
摘要
The ground state properties of 132Sn at equilibrium and at large compression are investigated, within the framework of the radially constrained spherical HartreeFock(CSHF) approximation. The delta resonance effects on the properties of neutronrich double magic spherical nucleus, 132Sn, in its ground state and the state under static compression are studied. The sensitivity of the nucleon size and Δ model spaces is investigated. At equilibrium, mixing between nucleon and Δ’s in the largest model space of nine major nucleon shells plus 10 Δ orbitals was found. Expanding the nucleon model space has a larger effect on reducing the static compression modulus and softening the nuclear equation of state than increasing the number of Δ states. It was found that the most of the increase in the nuclear energy generated under compression is used to create the massive Δ particles. For 132Sn nucleus under compression at 12 times the normal nuclear density, the excited nucleons to Δ’s increased sharply up to 13% of the total number of constituents. This result is consistent with the values extracted from relativistic heavyion collisions. The single particle energy levels calculated and their behaviors under compression are examined too. A good agreement between results with effective Hamiltonian and the phenomenological shell model for the low lying singleparticle spectra is obtained.