  Two-nucleon transfer reactions are essential tools to investigate specific
features of the nuclearstructure such as the correlation among valence
particles in the transfer process. Besides, transfer reactions may be an
important channel to take into account in charge exchange processes since they
can represent a competing contribution to the final cross section. The
two-proton pickup transfer reaction 40Ca(18O,20Ne)38Ar has been measured at 270
MeV and the angular distributions for transitions to different excited states
extracted. This work shows the analysis of the data performed by finite range
coupled reaction channel and coupled channel Born approximation methods.
Extensive shell-model calculations are performed to derive the one- and
two-proton spectroscopic amplitudesfor the projectile and target overlaps. The
role of the simultaneous and sequential two-proton transfer mechanisms to
populate the measured final states or groups of states, mainly characterized by
ahigh collectivity, is also discussed.

Nuclear Experiment;Nuclear Theory