J. Carter

Complete electric dipole response and the neutron skin in 208Pb

A benchmark experiment on (208)Pb shows that polarized proton inelastic scattering at very forward angles including 0° is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r(skin) = 0.156(-0.021)(+0.025) fm in (208)Pb derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars.

Pygmy dipole resonance in 208Pb

Scattering of protons of several hundred MeV is a promising new spectroscopic tool for the study of electric dipole strength in nuclei. A case study of 208 Pb shows that, at very forward angles, J π = 1 − states are strongly populated via Coulomb excitation. A separation from nuclear excitation of other modes is achieved by a multipole decomposition analysis of the experimental cross sections based on theoretical angular distributions calculated within the quasiparticle-phonon model. The B(E1) transition strength distribution is extracted for excitation energies up to 9 MeV; that is, in the region of the so-called pygmy dipole resonance (PDR). The Coulomb-nuclear interference shows sensitivity to the underlying structure of the E1 transitions, which allows for the first time an experimental extraction of the electromagnetic transition strength and the energy centroid of the PDR.

Isotopic production cross sections in proton-nucleus collisions at 200 MeV

Intermediate-mass fragments from the interaction of

Quasi-elastic nucleon transfer and single charge exchange in 48Ti + 42Ca collisions

^{27}\mathrm{Al}

Elastic and inelastic scattering of 16O and 12C by 24Mg near the Coulomb barrier

,

Quasi-elastic single-nucleon transfer in 48Ti + 42,44Ca collisions well above the Coulomb barrier

^{59}\mathrm{Co}

Elastic and inelastic scattering in the 6Li, 9Be + 12C systems: excitation of unbound excited states and cluster transfers

, and

Inelastic scattering in the 6Li + 9Be system leading to unbound excited states of either nucleus

^{197}\mathrm{Au}

Fine structure of the isoscalar giant quadrupole resonance in 40Ca due to Landau damping

with 200-MeV protons were measured in an angular range from

Isoscalar quadrupole strength in 40Ca from the (p,p′α0) reaction at Ep = 100 MeV

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