title: Universality in molecular halo clusters.
abstract: The ground state of weakly bound dimers and trimers with a radius extending well into the classically forbidden region is explored, with the goal to test the predicted universality of quantum halo states. The focus of the study is molecules consisting of T↓, D↓, ^{3}He, ^{4}He, and alkali atoms, where the interaction between particles is much better known than in the case of nuclei, which are traditional examples of quantum halos. The study of realistic systems is supplemented by model calculations in order to analyze how low-energy properties depend on the interaction potential. The use of variational and diffusion Monte Carlo methods enabled a very precise calculation of both the size and binding energy of the trimers. In the quantum halo regime, and for large values of scaled binding energies, all clusters follow almost the same universal line. As the scaled binding energy decreases, Borromean states separate from tango trimers.
authors.affiliation: Faculty of Science, University of Split, HR-21000 Split, Croatia.
authors.forename: P
authors.initials: P
authors.lastname: Stipanović
authors.affiliation: Faculty of Science, University of Split, HR-21000 Split, Croatia and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716-2593, USA.
authors.forename: L Vranješ
authors.initials: LV
authors.lastname: Markić
authors.affiliation: Faculty of Science, University of Split, HR-21000 Split, Croatia and Departament de Física i Enginyeria Nuclear, Campus Nord B4-B5, Universitat Politècnica de Catalunya, E-08034 Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Bešlić
authors.affiliation: Departament de Física i Enginyeria Nuclear, Campus Nord B4-B5, Universitat Politècnica de Catalunya, E-08034 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Boronat