Inelastic and elastic collision rates for triplet states of ultracold   strontium
  We report measurement of the inelastic and elastic collision rates for ^{88}Sr atoms in the (5s5p)^3P_0 state in a crossed-beam optical dipole trap. This is the first measurement of ultracold collision properties of a ^3P_0 level in an alkaline-earth atom or atom with similar electronic structure. Since the (5s5p)^3P_0 state is the lowest level of the triplet manifold, large loss rates indicate the importance of principle-quantum-number-changing collisions at short range. We also provide an estimate of the collisional loss rates for the (5s5p){^3P_2} state. 
A. Traverso, R. Chakraborty, Y. N. Martinez de Escobar, P. G.   Mickelson, S. B. Nagel, M. Yan, and T. C. Killian