Production of four-quark states with double heavy quarks at LHC

We study the hadronic production of four-quark states with double heavy quarks and double light antiquarks at LHC. The production mechanism involves a color anti-triplet diquark cluster consisting of double heavy quarks that is formed from the double heavy quark-antiquark pairs via the gg fusion hard process first, followed by the fragmentation of the diquark cluster into a four-quark (tetraquark) state. Predictions for the production cross sections and their differential distributions are presented. Our results show that it is promising to discover these tetraquark states in LHC experiments both for large number events and for the unique decay signatures in detectors.