Pygmy resonances and neutron skins

Journal Article · Tue Mar 15 04:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.83.034319· OSTI ID:21499488

Piekarewicz, J ^[1]

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1. Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)

In a study motivated by a recent experiment, the distribution of electric dipole strength in the neutron-rich {sup 68}Ni isotope was computed using a relativistic random-phase approximation with a set of effective interactions that - although well calibrated - predict significantly different values for the neutron-skin thickness in {sup 208}Pb. The emergence of low-energy 'pygmy' strength that exhausts about 5%-8% of the energy-weighted sum rule (EWSR) is clearly identified. In addition to the EWSR, special emphasis is placed on the dipole polarizability. In particular, our results suggest a strong correlation between the dipole polarizability of {sup 68}Ni and the neutron-skin thickness of {sup 208}Pb. Yet we find a correlation just as strong, and an even larger sensitivity, between the neutron-skin thickness of {sup 208}Pb and the fraction of the dipole polarizability exhausted by the pygmy resonance. These findings suggest that dipole polarizability may be used as a proxy for the neutron skin.

• OSTI ID: 21499488
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 3 Vol. 83; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
APPROXIMATIONS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCULATION METHODS
COMPUTERIZED SIMULATION
CORRELATIONS
DIMENSIONS
DIPOLES
DISTRIBUTION
ELECTRIC DIPOLES
ELECTRICAL PROPERTIES
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
EVEN-EVEN NUCLEI
FERMIONS
HADRONS
HEAVY NUCLEI
INTERACTIONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEAD 208
LEAD ISOTOPES
MULTIPOLES
NEUTRON-RICH ISOTOPES
NEUTRONS
NICKEL 68
NICKEL ISOTOPES
NUCLEI
NUCLEONS
PHYSICAL PROPERTIES
POLARIZABILITY
RADIOISOTOPES
RANDOM PHASE APPROXIMATION
RELATIVISTIC RANGE
RESONANCE
SENSITIVITY
SIMULATION
STABLE ISOTOPES
SUM RULES
THICKNESS