Effect of repulsive and attractive three-body forces on nucleus-nucleus elastic scattering

Abstract

The effect of the three-body force (TBF) is studied in nucleus-nucleus elastic scattering on the basis of Brueckner theory for nucleon-nucleon (NN) effective interaction (complex G matrix) in the nuclear matter. A new G matrix called CEG07 proposed recently by the present authors includes the TBF effect and reproduces a realistic saturation curve in the nuclear matter, and it is shown to well reproduce proton-nucleus elastic scattering. The microscopic optical potential for the nucleus-nucleus system is obtained by folding the G matrix with nucleon density distributions in colliding nuclei. We first analyze in detail the 16 O + 16 O elastic scattering at E/A = 70 MeV. The observed cross sections are nicely reproduced up to the most backward scattering angles only when the TBF effect is included. The use of the frozen-density approximation (FDA) is essentially important to properly estimate the effect of the TBF in nucleus-nucleus scattering. Other prescriptions for defining the local density have also been tested, but only the FDA prescription gives a proper description of the experimental cross sections as well as the effect of the TBF. The effects of the three-body attraction and the ω-rearrangement term are also analyzed. The CEG07 interaction is compared with CDM3Y6, which is a reliable and successful effective density-dependent NN interaction used in the double-folding model. The CEG07 G matrix is also tested in the elastic scattering of 16 O by the 12 C, 28 Si, and 40 Ca targets at E/A = 93.9 MeV, and in the elastic scattering of 12 C by the 12 C target at E/A = 135 MeV with great success. The decisive effect of the TBF is clearly seen also in those systems. Finally, we have tested CEG07a, CEG07b, and CEG07c for the 16 O + 16 O system at various energies.

Repulsive nature of optical potentials for high-energy heavy-ion scattering

“…Recently, the present authors have proposed a theoretical model for constructing the complex optical potential for any composite projectiles through the double-folding-model (DFM) procedure by using a newly proposed complex Gmatrix NN interaction called CEG07 [15][16][17] and demonstrated that the folding model provides quite reliable complex optical potentials for intermediate-energy scattering of light heavy ions, such as 16 O and 12 C, by various target nuclei. One of the major findings of this paper is the discovery of the decisive role of the three-body force (TBF) effect (or that of the three-nucleon correlations in a nuclear medium).…”

“…The repulsive part of the TBF is found to be of particular importance, which contributes dominantly at the density region higher than the saturation density ρ 0 . Because of this repulsive effect, the strength of nucleus-nucleus potential is reduced strongly at short distances where densities of two nuclei overlap with each other [16,17]. The experimental data for elastic scattering of 16 O and 12 C projectiles by various target nuclei at E/A = 70-135 MeV are well reproduced over the whole angular range only when the G-matrix interactions with the TBF effects (CEG07b or CEG07c) are used in constructing the DFM potentials, while the data cannot be reproduced at all with the use of the CEG07a interaction generated from the two-body force only [17].…”

“…Because of this repulsive effect, the strength of nucleus-nucleus potential is reduced strongly at short distances where densities of two nuclei overlap with each other [16,17]. The experimental data for elastic scattering of 16 O and 12 C projectiles by various target nuclei at E/A = 70-135 MeV are well reproduced over the whole angular range only when the G-matrix interactions with the TBF effects (CEG07b or CEG07c) are used in constructing the DFM potentials, while the data cannot be reproduced at all with the use of the CEG07a interaction generated from the two-body force only [17]. Since the TBF effect in nuclear matter plays an essential role to make the saturation curve and the incompressibility K reasonable, these results imply that the proper nucleus-nucleus interaction models should be based on a consistent treatment of the properties of infinitenuclear matter and the optical potentials between interacting finite-nuclear systems.…”

Intermediate-energy Coulomb excitation ofSn104: ModerateE2strength decrease approachingDoornenbal1, Takeuchi2, Aoi3 et al. 2014Phys. Rev. CSelf Cite592280View full textAdd to dashboardCite

“…In order to extract δ, optical potentials were derived as described in Ref. [27] using the microscopic folding model with the complex G-matrix interaction CEG07 [28,29] and the density presented in Ref. [30].…”

ElasticO16+Ne20scattering from a folding model analysis

“…It has been shown that folding model potentials give a good account of the scattering between some 4N-type nuclei. For example, the 12 C+ 12 C, 16 28 Si elastic scattering data have been well described by folding potentials in diverse approaches [8][9][10][11][12][13][14][15][16]. However, for 16 O+ 20 Ne scattering, there is only one paper [17] involving a calculation using a folding potential; no other studies are available using a folding model to attempt to explain the 16 O+ 20 Ne scattering.…”