-Nucleon Tensor Force in Hypertriton

Abstract

The hypertriton ~H is the lightest and loosely bound hypernucleus and is of fundamental impor­ tiillce to get the knowledge of the A -nucleon interaction. Thereupon we examine the effect of A-N tensor force in the bound state of the hyper­ triton by solving the Faddeev equation in the coordinate .space, considering the fact that the neutron-proton tensor force plays an inportant role to make the realistic estimate of the binding energy in the hypertriton. The meson theoretical A-N potential due to one boson exchange (OBE) has been proposed by N agels et al. I) in order to reproduce the available nucleon-nucleon and hyperon-nucleon scattering data, where the latest ones are the model D and F. Since the tensor force of the model D is stronger than that of the model F, it is more effective to examine a local A-N potential including the tensor force with repulsive soft core based on this OBE model D potential, where the explicit AN-2:N coupling is not introduced. We previously estimated the A -separation energy BA of the hypertriton using the effective central A -N potential with three term Yukawa form including the repulsive soft core and the Reid soft core n-p potential including the tensor force 2 ) by solving the Faddeev equation in the coordinate space and obtained the BA value of 0.17 MeV. 3 ) It was then pointed out that the n-p tensor force is important for the bound state of the hypertriton. Gibson and Lehman re-evaluat­ ed the A -separation energy BA of ~H using the A-N separable central potential and also n-p separable potential including the tensor force by solving the Faddeev equation in the momentum space.') Their results for BA were 0.13 MeV