The 12+ state of 3H and 3He below the break-up threshold: (II). Gammel-Brueckner potential

Results for the $\text{J}{}^{\mathrm{\pi }}\text{=}\text{1}\text{2}{}^{\mathrm{+}}$ state of ³H and ³He using the Gammel-Brueckner (GB) nucleon-nucleon potential are presented. Comparison is made with the predictions of the Hamada-Johnston (HJ) potential for bound-state properties and N-d scattering. Whilst the GB potential gives an ³He binding energy at ?7.75 MeV which is close to experiment, the Coulomb energy still remains low. The minimum in the electron scattering charge form factor is in worse agreement with experiment than HJ whilst the secondary maximum shows insufficient enhancement over the HJ results. The N-d doublet scattering length is closer to experiment than the results for HJ but there still appears to be a discrepancy with experiment. These results partially support the suggestion that a two-nucleon potential of HJ type with a larger hard-core radius than HJ, but fitted to a smaller deuteron D-state probability, may give a reasonable representation of the three-nucleon data apart from the Coulomb energy. Evidence now appears strong from this latter parameter for a small charge asymmetry in the two-nucleon potential.