Study of Doubly Heavy Baryon Spectrum via QCD Sum Rules
  In this work, we calculate the mass spectrum of doubly heavy baryons with the diquark model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquark field and a light quark field. Contributions of the operators up to dimension six are taken into account in the operator product expansion. Within a reasonable error tolerance, our numerical results are compatible with other theoretical predictions. This indicates that the diquark picture reflects the reality and is applicable to the study of doubly heavy baryons. 
Liang Tang, Xu-Hao Yuan, Cong-Feng Qiao, Xue-Qian Li
hep-ph