Λ_c Enhancement from Strongly Coupled Quark-Gluon Plasma

We propose the enhancement of Λ_c as a novel quark-gluon plasma signal in heavy ion collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider. Assuming a stable bound diquark state in the strongly coupled quark-gluon plasma near the critical temperature, we argue that the direct two-body collision between a c quark and a [ud] diquark would lead to an enhanced Λ_c production in comparison with the normal three-body collision among independent c, u, and d quarks. In the coalescence model, we find that the Λ_c/D yield ratio is enhanced substantially due to the diquark correlation.