Three-body calculations forthe K⁻pp system within potential models

We present three-body nonrelativistic calculations within the framework of a potential model for the kaonic cluster K ⁻ pp using two methods: the method of hyperspherical harmonics in the momentum representation and the method of Faddeev equations in configuration space. To perform numerical calculations, different NN and antikaon–nucleon interactions are applied. The results of the calculations for the ground-state energy for the K ⁻ pp system obtained by both methods are in reasonable agreement. Although the ground-state energy is not sensitive to the pp interaction, it shows very strong dependence on the K ⁻ p potential. We show that the dominant clustering of the $K^{-}pp$ system in the configuration Λ (1405) + p allows us to calculate the binding energy to good accuracy within a simple cluster approach for the differential Faddeev equations. The theoretical discrepancies in the binding energy and width for the K ⁻ pp system related to the different pp and K ⁻ p interactions are addressed. (paper)