2000/03/13 by J. Piekarewicz · 2 citations
Physics and Astronomy · #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #Quantum, superfluid, helium dynamics #astro-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevc.62.051304
published as Phys.Rev. C62 (2000) 051304 · 4 Revtex pages and 3 eps figures; submitted to PRC
arxiv created 2000/03/13 · openalex publication_date 2000/10/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We calculate the longitudinal response of 208Pb using a relativistic random-phase approximation to three different parametrizations of the Walecka model with scalar self-interactions. From a nonspectral calculation of the response---which automatically includes the mixing between positive- and negative-energy states---we extract the distribution of strength for the isoscalar monopole, dipole, and high-energy octupole resonances. We employ a consistent formalism that uses the same interaction in the calculation of the ground state as in the calculation of the response. As a result, the conservation of the vector current is strictly maintained throughout the calculation. Further, the spurious dipole strength---associated with the uniform translation of the center of mass---gets shifted to zero excitation energy and is cleanly separated from the physical excitations. The best description of the collective modes is obtained using a ``soft'' parametrization having a compression modulus of K=224 MeV.