We experimentally investigate three-body recombination loss in a gas of ultracold 7Li atoms prepared in two different spin states in the vicinity of two different Feshbach resonances. We report that in the regime of universality the positions and widths of recombination minima for positive scattering lengths and Efimov resonances for negative scattering lengths are identical for both states within the experimental errors. The absolute locations and lifetimes of Efimov features are defined by the short-range part of the three-body potential which is usually treated in terms of a three-body parameter [1]. Therefore our measurements indicate that the three body parameter at high magnetic fields is spin independent [2,3]. Moreover, we found that the relation between locations of the observed features are in an excellent agreement with the universal theory and in that sense we support the famous universal scaling factor 22.7.

[1] E. Braaten, H.-W. Hammer, "Universality in few-body systems with large scattering length'', Phys. Rep. 428, 259 (2006).

[2] N. Gross, Z. Shotan, S.J.J.M.F. Kokkelmans and L. Khaykovich "Observation of universality in ultracold 7Li three-body recombination'', Phys. Rev. Lett. 103, 163202 (2009).

[2] N. Gross, Z. Shotan, S.J.J.M.F. Kokkelmans and L. Khaykovich, "Nuclear-spin-independent short-range three-body physics in ultracold atoms'', Phys. Rev. Lett. 105, 103203 (2010).