Measurements of ISGMR in Sn, Cd and Pb isotopes and the asymmetry of nuclear matter incompressibility

Journal Article · Fri Oct 28 04:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3628374· OSTI ID:21612043

Fujiwara, M; Hashimoto, H; Nakanishi, K; Okumura, S; Yosoi, M ^[1]; Li, T; Patel, D; Garg, U; Berg, G P. A.; Liu, Y; Marks, R; Matta, J; Nayak, B K; Madhusudhana-Rao, P V; Long, A; Sault, K; Talwar, R ^[2]; Ichikawa, M; Itoh, M; Matsuo, R ^[3]

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1. Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan)
2. JINA and Physics Department, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
3. Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan)

The compression-mode isoscalar giant monopole resonance (ISGMR) has been studied in the Sn, Cd and Pb isotopes using inelastic scattering of 400 MeV {alpha}-particles at extreme forward angles, including 0 deg. We have obtained completely 'background-free' inelastic-scattering spectra for the Sn, Cd, and Pb isotopes for a wide angular and excitation-energy range. The various giant resonances excited with different transferred angular momenta were extracted by a multipole-decomposition analysis (MDA). It was found that the centroid energies of the ISGMR in Sn isotopes are significantly lower than the theoretical predictions. The K{sub {tau}} in the empirical expression for the nuclear incompressibility has been determined to be K{sub {tau}} = -550{+-}100 MeV for the Sn isotopes. The extracted value for the Cd isotopes is K{sub {tau}} = -480{+-}100 MeV. These numbers are consistent with values of K{sub {tau}} = -370{+-}120 MeV obtained from an analysis of the isotopic transport ratios in medium-energy heavy-ion reactions, K{sub {tau}} -500{sub -100}{sup +120} MeV obtained from constraints placed by neutron-skin data from anti-protonic atoms across the mass table, and K{sub {tau}} = -500{+-}50 MeV obtained from theoretical calculations using different Skyrme interactions and relativistic mean field (RMF) Lagrangians. Stringent constraints on interactions employed in nuclear structure calculations are obtained on the basis of the experimentally determined values for K{sub {infinity}} and K{sub {tau}}. These parameters constrain as well the equation of state (EOS) of nuclear matter. However, a significant discrepancy still remains. The ISGMR positions in Sn and Cd isotopes are systematically lower than the predictions obtained on basis of determined from the ISGMR in {sup 208}Pb. This raises the question ''Why are Sn and Cd nuclei so soft?''. For a clue to solve the problem, we discuss the preliminary results on the exact positions of the ISGMR in {sup 204,206,208}Pb.

• OSTI ID: 21612043
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1377; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
BARYONS
CADMIUM ISOTOPES
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EQUATIONS
EQUATIONS OF STATE
EVEN-EVEN NUCLEI
EXCITATION
FERMIONS
FIELD THEORIES
FUNCTIONS
GIANT RESONANCE
HADRONS
HEAVY ION REACTIONS
HEAVY NUCLEI
INELASTIC SCATTERING
ISOTOPES
LAGRANGIAN FIELD THEORY
LAGRANGIAN FUNCTION
LEAD 208
LEAD ISOTOPES
MATTER
MEAN-FIELD THEORY
MEV RANGE
NEUTRONS
NUCLEAR MATTER
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
NUCLEI
NUCLEON-NUCLEON POTENTIAL
NUCLEONS
POTENTIALS
QUANTUM FIELD THEORY
RELATIVISTIC RANGE
RESONANCE
SCATTERING
SKYRME POTENTIAL
STABLE ISOTOPES
TIN ISOTOPES