1Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918(4), Beijing 100039 2CCAST (World Laboratory), PO Box 8730, Beijing 100080 3Department of Physics, Peking University, Beijing 100871
We present a way to calculate tetraquarks ratios for quark--gluon plasma with diquarks. The ratios of tetraquarks over baryons produced from quark matter are high than hadronic gas model limits. It is a better way to search for four-quark states in relativistic heavy ion collisions. It may become a criterion to judge whether quark--gluon plasma has formed to search for four-quark states in relativistic heavy ion collisions.