title: Collisional properties of ultracold K-Rb mixtures.
abstract: We determine the interspecies s-wave triplet scattering length a(3) for all K-Rb isotopic mixtures by measuring the elastic cross section for collisions between 41K and 87Rb in different temperature regimes. The positive value a(3)=+163(+57)(-12)a(0) ensures the stability against collapse of binary (41)K- (87)Rb Bose-Einstein condensates. For the fermion-boson mixture (40)K- (87)Rb, we obtain a large and negative scattering length which implies an efficient sympathetic cooling of the fermionic species down to the degenerate regime.
authors.affiliation: European Laboratory for Nonlinear Spectroscopy and Dipartimento di Fisica, Universitá di Firenze, and INFM, 50019 Sesto Fiorentino, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ferrari
authors.forename: M
authors.initials: M
authors.lastname: Inguscio
authors.forename: W
authors.initials: W
authors.lastname: Jastrzebski
authors.forename: G
authors.initials: G
authors.lastname: Modugno
authors.forename: G
authors.initials: G
authors.lastname: Roati
authors.forename: A
authors.initials: A
authors.lastname: Simoni