Luneburg-lens-like structural Pauli attractive core of the nuclear force at short distances

A recent paper Ohkubo (2017) [1] found that the measured S01 phase shifts can be reproduced using a deeply attractive nucleon-nucleon potential. We find that the deuteron would decay strongly via pion emission to the deeply bound state arising in this potential. Therefore the success of a deeply attractive potential in describing phase shifts must be regarded only as an interesting curiosity.