Giant quadrupole resonances in 208Pb, the nuclear symmetry energy, and the neutron skin thickness

Scientific paper - Original scientific paper

• Author: X. Roca-Maza
• Author: M. Brenna
• Author: B. K. Agrawal
• Author: P. F. Bortignon
• Author: G. Colo
• Author: Li-Gang Cao
• Author: Nils Paar
• Author: Dario Vretenar
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Recent improvements in the experimental determination of properties of the isovector giant quadrupole resonance (IVGQR), as demonstrated in the A=208 mass region, may be instrumental for characterizing the isovector channel of the effective nuclear interaction. We analyze properties of the IVGQR in 208Pb, using both macroscopic and microscopic approaches. The microscopic method is based on families of nonrelativistic and covariant energy density functionals (EDF), characterized by a systematic variation of isoscalar and isovector properties of the corresponding nuclear matter equations of state. The macroscopic approach yields an explicit dependence of the nuclear symmetry energy at some subsaturation density, for instance S(ρ=0.1 fm−3), or the neutron skin thickness Δrnp of a heavy nucleus, on the excitation energies of isoscalar and isovector GQRs. Using available data it is found that S(ρ=0.1 fm−3)=23.3±0.6 MeV. Results obtained with the microscopic framework confirm the correlation of the Δrnp to the isoscalar and isovector GQR energies, as predicted by the macroscopic model. By exploiting this correlation together with the experimental values for the isoscalar and isovector GQR energies, we estimate Δrnp=0.14±0.03 fm for 208Pb, and the slope parameter of the symmetry energy: L=37±18 MeV.

• Keywords (english): giant quadrupole resonance; symmetry energy; neutron skin; nuclear energy density functional; quasiparticle random phase approximation
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C - Nuclear Physics
• Numbering: vol. 87, no. 3, 034301
• p-ISSN: 0556-2813
• e-ISSN: 1089-490X
• DOI: https://doi.org/10.1103/PhysRevC.87.034301
• URN:NBN: urn:nbn:hr:217:939358
• Publication: 2013
• Project: Number: 119-1191005-1010; Title (croatian): Nuklearna struktura i nuklearna astrofizika; Leader: Dario Vretenar; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: https://journals.aps.org/prc/abstract/10.1103/PhysRevC.87.034301
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2013) by the American Physical Society. Received 18 December 2012; published 1 March 2013.
• Created on: 2019-11-24 14:25:37