One-proton removal from neutron-rich carbon isotopes in C12–16 beams near 240 MeV/nucleon beam energy

The inclusive cross sections of one-proton removal from neutron-rich carbon isotopes ¹³⁻⁻¹⁵C on a carbon target near 2400.16em0exMeV/nucleon were measured at the External Target Facility, HIRFL-CSR (Heavy Ion Research Facility in Lanzhou, Cooler Storage Ring). Together with the data for ¹²C and ¹⁶C at similar energies, the measurements are compared with Glauber model predictions weighted by spectroscopic strengths calculated by various shell models, namely standard shell model (SM), Gamow shell model (GSM), and no-core shell model (NCSM), which differ in the amount and aspects of included internucleon correlations. The dependencies of the spectroscopic strength reduction factor Rₛ on the binding depth ΔS of the removed proton are plotted. The obtained Rₛ-ΔS relations of GSM and SM turn out to be largely consistent with the earlier-observed systematics, whereas the NSCM Rₛ exhibit an appreciable overall increase. GSM and NCSM predictions both compare better with experiment than SM and tend to alleviate the odd-even staggering of Rₛ against projectile mass number A. The Rₛ of ¹⁵C is intriguingly large compared with the rather low Rₛ of ¹⁶C, for which the reason is discussed.