# Four-body calculation of ${}^2\mathrm{H}(d,p){}^3\mathrm{H}$ and ${}^2\mathrm{H}(d,n){}^3\mathrm{He}$ reactions above breakup threshold

## TL;DR

This paper presents a precise four-body calculation of deuteron-deuteron reactions above breakup threshold, accurately predicting various observables and comparing well with experimental data, highlighting some discrepancies at specific energies.

## Contribution

It introduces an exact four-body momentum-space approach to model deuteron-deuteron reactions above breakup threshold, including Coulomb effects and realistic potentials.

## Key findings

- Good agreement with experimental cross sections and analyzing powers.
- Discrepancies at minima of differential cross sections at higher energies.
- Differences in outgoing nucleon polarization at lower energies.

## Abstract

Nucleon transfer reactions in deuteron-deuteron collisions at energies above the three- and four-body breakup threshold are described using exact four-body equations for transition operators that are solved in the momentum-space framework. Differential cross sections, analyzing powers, polarizations, and spin transfer coefficients are obtained using realistic two-nucleon potentials and including the Coulomb repulsion between protons. Overall good agreement between predictions and experimental data is found. Most remarkable discrepancies are seen around the minima of the differential cross section at higher energies and in the outgoing nucleon polarization at lower energies.