2022 Impact factor 2.7
Hadrons and Nuclei
Eur. Phys. J. A 16, 371-379 (2003)
DOI: 10.1140/epja/i2001-10270-4

Implication of proton-nucleus scattering for density distributions of unstable nuclei

M. Rashdan

Department of Mathematics and Theoretical Physics, Atomic Energy Authority, Cairo, Egypt


(Received: 1 December 2001 / Revised version: 5 July 2002 / Published online: 18 February 2003)

The use of elastic proton scattering at intermediate and high energies to obtain information about the density distributions of unstable nuclei is investigated. A comparison between the relativistic impulse approximation (RIA) and Glauber model for proton scattering from $\chem{^{16}O}$, $\chem{^{40}Ca}$, $\chem{^{44}Ca}$ and $\chem{^{48}Ca}$ at medium energies is performed. We used density distributions derived from the relativistic mean-field theory, employing the recent relativistic force NL-RA1, as well as experimental and phenomenological densities. It is found that the eikonal approximation can describe the cross-section only at small scattering angles and is weakly sensitive to the density distributions, while the RIA nicely produced the experimental cross-sections, even at medium and larger angles, and was very sensitive to the nuclear densities. Furthermore, the RIA better describes the isospin dependence of the cross-section. We used the RIA to investigate the density distribution of $\chem{^{58}Ca}$ for proton scattering at different energies. It is found that the cross-section strongly depends on the parameters of the density distribution even at a small scattering angle. These results are important in extracting information about the structure of unstable nuclei. We also investigated the RIA and its sensitivity in describing halo nuclei such as $\chem{^{6}He}$. We used for $\chem{^{6}He}$ a no-halo Gaussian density and a realistic-halo density that derived in the cluster orbital shell model approximation and contains the extended distribution of the valence nucleons. Comparison with the recent experimental data at GSI at 717 MeV/nucleon shows that the RIA successfully described the data at all considered range of the momentum transfer and on the other hand favor the halo structure of $\chem{^{6}He}$.

24.10.Jv - Relativistic models.
25.60.-t - Reactions induced by unstable nuclei.

© Società Italiana di Fisica, Springer-Verlag 2003