We report the first observation of $K^{ \star}(892)^{ 0}\to\pi K$ in relativistic heavy ion collisions. The transverse momentum spectrum of $(K^{ \star0}+\bar{ K}^{ \star0})/2$ from central Au+Au collisions at $\sqrt{ s_{ _{ NN}}}=130$ GeV is presented. The ratios of the $K^{ \star0}$ yield derived from these data to the yields of negative hadrons, charged kaons, and $\phi$ mesons have been measured in central and minimum bias collisions and compared with model predictions and comparable $e^{ +}e^{ -}$, $pp$, and $\bar{ p}p$ results. The data indicate no dramatic reduction of $K^{ \star0}$ production in relativistic heavy ion collisions despite expected losses due to rescattering effects.
Categories: nucl-ex