We suggest a new Gogny-type finite-range effective interaction including a third Gaussian in the central term. Based on simple arguments valid for an arbitrary radial form factor, the three ranges are obtained in connection with physical grounds, relating them to one-boson exchange interactions. Moreover, some parameters of the longest range are fixed through the G-matrix elements of the One Pion Exchange Potential. On top of giving a fairly good description of atomic nuclei properties comparable with other existing parametrisations, the resulting interaction leads to a remarkable improvement of some infinite matter properties that are relevant for astrophysical calculations.

We present a new Gogny-type finite-range effective interaction including a third Gaussian in the central term. Based on simple arguments valid for an arbitrary radial form factor, the three ranges are fixed from physical grounds, relating them to one-boson exchange interactions. Moreover, some parameters of the longest range are fixed through the G-matrix elements of the One Pion Exchange Potential. On top of giving a fairly good description of atomic nuclei properties, the resulting interaction leads to a remarkable improvement of some infinite matter properties that are relevant for astrophysical calculations.

Background: Mg-24 is a strongly deformed nucleus in the ground state. Deformation effects can be observed in the structure of the isoscalar giant monopole and quadrupole resonances. Mg-24 is also a nucleus that is well known to present different types of cluster-oscillation modes. Both giant resonances and cluster states are strongly populated by isoscalar transitions. Purpose: To extract the E0, E1, and E2 transition strengths via Li-6 scattering. The Li-6 probe is a powerful tool for investigating the isoscalar nuclear response with a very favorable ratio of resonance-to-continuum background. Method: Double-differential cross sections of Li-6 inelastic scattering, at the beam energy of 100 MeV/u, were measured in the excitation-energy range 10-40 MeV and scattering angles 0-3 degrees. A multipole-decomposition analysis was performed for extracting the isoscalar E0, E1, and E2 strength distributions. Results: The extracted multipole strengths were compared with predictions from consistent quasiparticle random phase approximation calculations. The theoretical predictions are in fair agreement with the experimental data. The E0 strength was also compared with results from antisymmetrized molecular dynamics calculations found in the literature. A few peaks in the experimental data might be associated with clustering in Mg-24. Conclusions: Ground-state deformation effects were observed in the isoscalar giant monopole resonance (ISGMR) and isoscalar giant quadrupole resonance (ISGQR) distributions. The ISGMR strength is split in two peaks around 19 and 28 MeV. The ISGQR exhibits a pronounced peak at 20 MeV with a broadening at the low-energy region, similar to predictions from microscopic calculations. Signatures of excitation of cluster states were observed in the E0 response. Further studies including particle-decay measurements will be required to confirm the nature of the observed peaks.

Inelastic ^6Li scattering at 100 MeV/u on ^12C and ^93Nb have been measured with the high-resolution magnetic spectrometer Grand Raiden. The magnetic-rigidity settings of the spectrometer covered excitation energies from 10 to 40 MeV and scattering angles in the range 0^∘ < θ_lab.< 2^∘. The isoscalar giant monopole resonance was selectively excited in the present data. Measurements free of instrumental background and the very favorable resonance-to-continuum ratio of ^6Li scattering allowed for precise determination of the E0 strengths in ^12C and ^93Nb. It was found that the monopole strength in ^12C exhausts 52 ± 3^(stat.)± 8 ^(sys.)% of the energy-weighted sum rule (EWSR), which is considerably higher than results from previous α-scattering experiments. The monopole strength in ^93Nb exhausts 92 ± 4^(stat.)± 10 ^(sys.)% of the EWSR, and it is consistent with measurements of nuclei with mass number of A≈90. Such comparison indicates that the isoscalar giant monopole resonance distributions in these nuclei are very similar, and no influence due to nuclear structure was observed.

Inelastic Li-6 scattering at 100 MeV/u on C-12 and Nb-93 has been measured with the high-resolution magnetic spectrometer Grand Raiden. The magnetic-rigidity settings of the spectrometer covered excitation energies from 10 to 40 MeV and scattering angles in the range 0 degrees < theta(lab). < 2 degrees. The isoscalar giant monopole resonance was selectively excited in the present data. Measurements free of instrumental background and the very favorable resonance-to-continuum ratio of Li-6 scattering allowed for precise determination of the E0 strengths in C-12 and Nb-93. It was found that the monopole strength in C-12 exhausts 52 +/- 3(()(stat)(.)) +/- 8((sys.))% of the energy-weighted sum rule (EWSR), which is considerably higher than results from previous alpha-scattering experiments. The monopole strength in Nb-93 exhausts 92 +/- 4(()(stat)(.)) +/- 10((sys.))% of the EWSR, and it is consistent with measurements of nuclei with mass number of A approximate to 90. Such comparison indicates that the isoscalar giant monopole resonance distributions in these nuclei are very similar, and no influence due to nuclear structure was observed.