Odd-even staggering of reaction cross sections for ${}^{22,23,24}$O isotopes

The interaction cross sections of ${}^{22,23}$O nuclei at 900 MeV/nucleon have been measured recently by Kanungo et al. [Phys. Rev. C 84, 061304(R) (2011)]. We show that the odd-even staggering parameter of interaction cross sections deduced from these new data agrees well with the theoretical systematics expected for the neutron separation energy of $S_n=2.74\pm 0.120$ MeV for ${}^{23}$O. We also discuss briefly the energy dependence of the staggering parameter.

Figure 1

The staggering parameter ${\gamma }_3$ for ${}^{22,23,24}\mathrm{O}+{}^{12}\mathrm{C}$ reactions as a function of the neutron separation energy S${}_n$ for the ${}^{23}$O nucleus. The solid and the dashed lines correspond to the staggering parameters for the incident energies of $E=1000$ MeV/nucleon and $E=240$ MeV/nucleon, respectively. The solid triangle and the solid circle are the experimental staggering parameters extracted with the experimental data of Refs. [4] and [8], respectively, plotted at the empirical separation energy, $S_n=2.74\pm 0.120$ MeV.