Strong enhancement of two-proton transfer in the 40Ca(37Cl,39K)38Ar - reaction
Measurements of one- and two-proton transfer in the system 37Cl + 40Ca at energies close to the Coulomb barrier have been performed. The two-proton transfer to ground states attains cross sections which are comparable to the one-proton transfer. The strong enhancement of the proton-pair transfer is interpretedinterms of a combined actionofstatic and dynamic proton-proton correlations, for example in the 2+ state of 38Ar andin the 0+ ground state of40Ca which are introducedbymixing of shell model configurations across two major shells with h̅ω = 2 and 3 of different parities (s1/2, d3/2 and f7/2, p3/2). This effect, which is called hybridization, induces a strong spatial polarization of the nucleons in the two-proton wave-function and enhances the two-proton transfer cross section. Coupled reaction channel calculations reproduce consistently the one and two proton transfer using spectroscopic information from light ion reactions.