Title: Measurement of three-body recombination coefficient of ultracold lithium and strontium atoms

Abstract: We report on the observation of a conspicuous loss in an ultracold mixture of $^{7}$Li and $^{88}$Sr atoms confined in a far-off-resonance optical dipole trap. We attribute the trap loss to the three-body inelastic Li-Sr-Sr collision and extract the corresponding three-body recombination coefficient $K_3$ at $T\sim 18.5,45,70,600$ $\mu K$. The measured three-body recombination coefficient is about two to three orders of magnitude larger than the typical values convenient for realizing quantum degenerate gases. It also indicates a potentially large $s$-wave scattering length between the bosonic $^{7}$Li and $^{88}$Sr atoms, and essentially rules out the prospect of realizing $^7$Li and $^{88}$Sr mixtures of high phase space density.