Analysis of two-proton transfer in the 40Ca(18O,20Ne)38Ar reaction at 270 MeV incident energy

TL;DR

This paper investigates two-proton transfer reactions in the 40Ca(18O,20Ne)38Ar system at 270 MeV, combining experimental measurements with advanced reaction modeling and shell-model calculations to understand transfer mechanisms and nuclear structure features.

Contribution

It provides a comprehensive analysis of two-proton transfer mechanisms using coupled reaction channel methods and shell-model calculations at a specific energy, highlighting the role of simultaneous and sequential transfers.

Findings

Both simultaneous and sequential transfer mechanisms contribute to populating excited states.

Shell-model calculations successfully derive spectroscopic amplitudes for the reaction.

Angular distributions reveal the importance of transfer mechanisms in nuclear structure insights.

Abstract

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.