Systematic extraction of the strong absorption distance and Coulomb barrier from elastic scattering*

Abstract

The reduced strong absorption distance $d_\mathrm{S}$ and the Coulomb barrier height $V_\mathrm{B}$ are extracted from the quarter-point recipe from a series of experimental elastic scattering angle distributions.The nuclei having different binding energies as the projectile are systematically studied, including the tightly bound, weakly bound, and halo nuclei. {It is found that the mean $d_\mathrm{S}$ for halo nuclei is significantly larger than that of the tightly bound and weakly bound nuclei. The complex behavior of $d_\mathrm{S}$ concerning the binding energy and properties of the target is observed for halo nuclei. }The linear relationship of the reduced distance with the system size could be used to estimate the Coulomb barrier radius $R_\mathrm{B}$, which is difficult to be obtained from fusion reactions. The rule of $V_\mathrm{B}$ concerning the Coulomb parameter $z$ is in agreement with other theoretical barrier laws extracted from the fusion reaction.Furthermore, the reason why the binding energy or deformation has little effect on the \textcolor{blue}{linear relationship} of $V_\mathrm{B}$ as a function of $z$ is manifested.

Elastic scattering of 13C and 14C isotopes on a 208Pb target at energies of approximately five times the Coulomb barriers*

“…6. For all datasets, σ/ was close to unity at larger distances but rapidly fell off when tending toward shorter distances owing to the strong absorption of the elastic flux into non-elastic channels [42]. The large dif- ferences between C and other carbon isotopes can be understood in terms of the combination of the reduced critical interaction distance and reduced strong interaction distance .…”

“…However, besides the incident energy difference, isospin asymmetry and valence particle separation energy were also different for these systems: C (S =4.006 MeV), C (S =4.946 MeV), C (S =8.177 MeV), and C (S =1.218 MeV). The larger values of , as also observed in the suppression of the Fresnel diffraction peak in the corresponding angular distributions [13,19], could be attributed to the low binding energies and/or couplings to other reaction channels [42,43]. However, note that the angular distribution of C+ Pb had fewer data points and larger error bars in the regions of interest.…”

“…Similar trends can be found in Refs. [42,43], where larger values of were observed for exotic nuclei compared with weakly and tightly bound nuclei. Note that the incident energies of were higher for C+ Pb, close to the barrier for C+ Pb, and both for C+ Pb.…”