Hypernuclei in halo/cluster effective field theory
The light double [Formula: see text] hypernuclei, [Formula: see text] and [Formula: see text], are studied as three-body [Formula: see text] and [Formula: see text] cluster systems in halo/cluster effective field theory at leading order. We find that the [Formula: see text] system in spin-0 channel does not exhibit a limit cycle whereas the [Formula: see text] system in spin-1 channel and the [Formula: see text] system in spin-0 channel do. The limit cycle is associated with the formation of bound states, known as Efimov states, in the unitary limit. For the [Formula: see text] system in the spin-0 channel we estimate the scattering length [Formula: see text] for [Formula: see text]-wave [Formula: see text] hyperon–hypertriton scattering as [Formula: see text][Formula: see text]fm. We also discuss that studying the cutoff dependences in the [Formula: see text] and [Formula: see text] systems, the bound state of [Formula: see text] is not an Efimov state but formed due to a high energy mechanism whereas that of [Formula: see text] may be regarded as an Efimov state.