The KK¯π decay of the f1(1285) and its nature as a K⁎K¯−cc molecule

We investigate the decay of f1(1285)→πKK¯ with the assumption that the f1(1285) is dynamically generated from the K⁎K¯−cc interaction. In addition to the tree level diagrams that proceed via f1(1285)→K⁎K¯−cc→πKK¯ , we take into account also the final state interactions of KK¯→KK¯ and πK→πK . The partial decay width and mass distributions of f1(1285)→πKK¯ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted mass distributions are significantly different from phase space and tied to the K⁎K¯−cc nature of the f1(1285) state