The continuum spectrum of hypernuclear trios
Martin Schäfer, Betzalel Bazak, Nir Barnea, J. Mareš
Abstract
The spectrum of hypernuclear trios composed of a Λ baryon and two nucleons is the subject of an ongoing experimental campaign, aiming to study the interaction of the Λ particle with a neutron, and the 3-body Λ-nucleon-nucleon force. In this manuscript we utilize baryonic effective field theory at leading order, constrained to reproduce the available low energy light hypernuclear data, to study the continuum spectrum of such hypernuclear trios. Using the complex scaling method and the inverse analytic continuation in the coupling constant method we find the existence of a virtual state in the Λnp Jπ=3/2+ channel, leading to cross-section enhancement near threshold. For the Λnn Jπ=1/2+ channel we predict a resonance state. Depending, however, on the value of the ΛN scattering length, the resonance pole moves from the physical to the unphysical complex energy sheet within the experimental bounds.