Low-lying resonances of 9ΛBe: Faddeev calculation with Padé-approximants

Configuration space Faddeev equations are applied to describe the 9 Λ Be hypernucleus in the αα Λ cluster model. For calculation of resonance state energies a variant of the method of analytical continuation in coupling constant is used. To realize this method, an auxiliary three-body potential is added to the Hamiltonian of the equations. A proper choice of strength parameter of the potential converts a resonance state into a bound state and an energy trajectory is obtained by variations of this parameter. To fulfill analytical continuation of this trajectory as a function of the strength parameter onto the complex plane, the Pade approximation is used. Spectrum of low-lying resonances is calculated with two α Λ phenomenological potentials. We predict existence of the 0 + 2 and 4 + 1 virtual states as well as the 2 + 2 resonance state near by the αα Λ threshold. The Be 8 ( L + ) + Λ ( s -wave ) configuration for description of the 9 Λ Be ground band is discussed.