Nature of the nn(J=1/2⁺, I=1) and ³H*(J=3/2⁺, I=0) states

The nature of the Lambda nn and H-3(Lambda)*(J(pi) = 3/2(+), I = 0) states is investigated within a pionless effective field theory at leading order, constrained by the low-energy Lambda N scattering data and hypernuclear three- and four-body data. Bound-state solutions are obtained using the stochastic variational method, and the continuum region is studied by employing two independent methods: the inverse analytic continuation in the coupling constant method and the complex scaling method. Our calculations yield both the Lambda nn and(Lambda)( 3)H* states unbound. We conclude that the excited state(Lambda)( 3)H* is a virtual state and the Lambda nn pole located close to the three-body threshold in a complex energy plane could convert to a true resonance with Re(E) > 0 for some considered Lambda N interactions. Finally, the stability of resonance solutions is discussed and limits of the accuracy of performed calculations are assessed.