Systematics of strong absorption radii and its relevance to the calculation of reaction cross sections

Abstract

Based on the detailed analysis of the reaction cross sections obtained using the finite range Glauber model, a systematic study of strong absorption radii is carried out. A simple phenomenological expression is proposed to calculate reaction cross sections directly using the average nucleon-nucleon cross section for a given target-projectile combination at given energy. Reliability of the model expression is demonstrated through a variety of illustrative examples.

Neutron density distribution and the halo structure ofC22

“…Further details of the calculations can be found in Ref. [11]. At high projectile energies, in the zero-range limit the FRGM reduces to ZRGM, as expected.…”

“…They have observed a large enhancement of proton reaction cross section 1338 ± 274 mb for 22 C as compared with 754 ± 22 mb for 19 C and 791 ± 34 mb for 20 C. Further, the separation energy for the two valence neutrons (S 2n ) in 22 C is only 420 ± 940 keV [3]. These results are very similar to those for the halo nucleus 11 Li.…”

“…A nuclear halo is a structure with dilute matter distribution far beyond the core of the nucleus. One of the most famous halo nuclei is 11 Li, discovered by Tanihata et al [2].…”

“…In summary, the recently measured [1] reaction cross sections for the neutron-rich carbon isotopes ( 19 C, 20 C, and 22 C) on a proton target at 40 A MeV are analyzed using the finite-range Glauber model (FRGM) [11] and the microscopic optical potential calculated within the Brueckner-Hartree-Fock formalism (BHF). The NN cross sections are used in FRGM while the Hamada-Johnston (HJ), Urbana v-14, and the Argonne v-18 internucleon potentials are employed in BHF to calculate the microscopic optical potential.…”