I. Usman

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

Abstract The fragmentation of the Isoscalar Giant Quadrupole Resonance (ISGQR) in 40Ca has been investigated in high energy-resolution experiments using proton inelastic scattering at E p = 200 MeV . Fine structure is observed in the region of the ISGQR and its characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The experimental scales are well described by Random Phase Approximation (RPA) and second-RPA calculations with an effective interaction derived from a realistic nucleon–nucleon interaction by the Unitary Correlation Operator Method (UCOM). In these results characteristic scales are already present at the mean-field level pointing to their origination in Landau damping, in contrast to the findings in heavier nuclei and also to SRPA calculations for 40Ca based on phenomenological effective interactions, where fine structure is explained by the coupling to two-particle–two-hole (2p–2h) states.

Wavelet signatures of K -splitting of the Isoscalar Giant Quadrupole Resonance in deformed nuclei from high-resolution (p,p ′ ) scattering off 146, 148, 150 Nd

Abstract The phenomenon of fine structure of the Isoscalar Giant Quadrupole Resonance (ISGQR) has been studied with high energy-resolution proton inelastic scattering at iThemba LABS in the chain of stable even-mass Nd isotopes covering the transition from spherical to deformed ground states. A wavelet analysis of the background-subtracted spectra in the deformed 146, 148, 150 Nd isotopes reveals characteristic scales in correspondence with scales obtained from a Skyrme RPA calculation using the SVmas10 parameterization. A semblance analysis shows that these scales arise from the energy shift between the main fragments of the K = 0 , 1 and K = 2 components.

Search for highly excited states in 28Si

CITATION: Montanari, D., et al. 2017. Search for highly excited states in ²⁸Si. Journal of Physics: Conference Series, 863(1):012051, doi:10.1088/1742-6596/863/1/012051.

CLUSTER STATES IN 12C AND 14C

The cluster structure of 12C is explored and recent measurements of proton inelastic scattering, suggesting a 2+ state close to 9.6 MeV are presented. Resonant scattering studies of 10Be + 4He used to populate resonances in 14C are briefly discussed.

A high energy-resolution zero degree facility for (p,p′) and (p,t) reactions

Medium-energy hadronic scattering and reactions at zero degrees are very selective to excitations with low angular momentum transfer. Only a few facilities exist worldwide where high energy-resolution measurements of this nature can be performed. The K600 Zero-Degree Facility at iThemba LABS, South Africa, was recently successfully developed. Measurements were performed for inelastic proton scattering at an incident energy of 200 MeV for targets ranging from 27Al to 208Pb. Excitation energy-resolution of 50 keV (FWHM) was achieved. A reasonable background subtraction procedure allows for the extraction of excitation energy spectra with low background. Measurements of the (p,t) reaction at 100 MeV benefit from a large difference in magnetic rigidity between the reaction products and primary particles, resulting in almost background-free spectra with excitation energy-resolution of 32 keV (FWHM).

Cluster states in C-12 and C-14

The cluster structure of 12C is explored and recent measurements of proton inelastic scattering, suggesting a 2+ state close to 9.6 MeV are presented. Resonant scattering studies of 10Be + 4He used to populate resonances in 14C are briefly discussed.

2{sup +} excitation of the {sup 12}C Hoyle state

A high-energy-resolution magnetic spectrometer has been used to measure the 12 C excitation energy spectrum to search for the 2 + excitation of the 7.65 MeV, 0 + Hoyle state. By measuring in the diffractive minimum of the angular distribution for the broad 0 + background, evidence is found for a possible 2 + state at 9.6(1) MeV with a width of 600(100) keV. The implications for the 8 Be + 4 He reaction rate in stellar environments are discussed.

Cluster Structure of 12Cand 11Be

The structure of 12C is discussed, in particular the spectrum of states above the α‐decay threshold. A search for the 2+ excitation of the Hoyle‐state is reported. The structural link between halo‐like states and molecular states is explored in the case of 11Be.

Cluster Structure of {sup 12}C and {sup 11}Be

The structure of 12C is discussed, in particular the spectrum of states above the α‐decay threshold. A search for the 2+ excitation of the Hoyle‐state is reported. The structural link between halo‐like states and molecular states is explored in the case of 11Be.