Four-nucleon system with $\Delta$-isobar excitation

Abstract

The four-nucleon bound state and scattering below three-body breakup threshold are described based on the realistic coupled-channel potential CD Bonn + $\Delta$ which allows the excitation of a single nucleon to a $\Delta$ isobar. The Coulomb repulsion between protons is included. In the four-nucleon system the two-baryon coupled-channel potential yields effective two-, three- and four-nucleon forces, mediated by the $\Delta$ isobar and consistent with each other and with the underlying two-nucleon force. The effect of the four-nucleon force on the studied observables is much smaller than the effect of the three-nucleon force. The inclusion of the $\Delta$ isobar is unable to resolve the existing discrepancies with the experimental data.

11 figures, to be published in Phys. Lett. B

References in corpus (3)

• Ab initio four-body calculation of n-3He, p-3H, and d-d scattering
• Four-body calculation of proton-3He scattering
• Low energy $n-\nuc{3}{H}$ scattering : a novel testground for nuclear interaction