Electromagnetic proton-neutron knockout off 16O: new achievements in theory

TL;DR

This paper presents advanced theoretical calculations of proton-neutron knockout reactions from 16O, highlighting the importance of center-of-mass effects, correlations, and orthogonalization in accurately predicting cross sections.

Contribution

It introduces a complete treatment of center-of-mass effects and orthogonalization in the theoretical modeling of 16O knockout reactions, improving upon previous approaches.

Findings

CM effects significantly increase cross sections in super-parallel kinematics.

Results are highly sensitive to the treatment of correlations.

Tensor and long-range correlations play crucial roles.

Abstract

Results for the cross sections of the exclusive 16O(e,e'pn)14N and 16O(gamma,pn)14N knockout reactions are presented and discussed in different kinematics. In comparison with earlier work, a complete treatment of the center-of-mass (CM) effects in the nuclear one-body current is considered in connection with the problem of the lack of orthogonality between initial bound and final scattering states. The effects due to CM and orthogonalization are investigated in combination with different treatments of correlations in the two-nucleon overlap function and for different parametrizations of the two-body currents. The CM effects lead in super-parallel kinematics to a dramatic increase of the 16O(e,e'pn) cross section to the 1_2^+ excited state (3.95 MeV) of 14N. In all the situations considered the results are very sensitive to the treatment of correlations. A crucial role is played by tensor correlations, but also the contribution of long-range correlations is important.