Properties of doubly charmed baryons in the quark-diquark model

Baryons containing two heavy quarks are important and interesting systems to study the quark-diquark structure of baryons and to understand the dynamics of QCD at hadronic scale. The Selex Collaboration has recently reported the discovery of $\Xi_{cc}$ with a mass of 3.519 Ge$V$. However, other groups such as Babar, Belle and Focus have all failed to confirm this state. So there is a demand to review this state both theoretically and experimentally. We report here the spectra and magnetic moments of $ccq(q\in u,d,s)$ systems using coulomb plus Martin potential. Here the two heavy quarks are considered for the diquark states. The same potential form is used for the diquark interaction as well as for the quark-diquark interaction. The chromomagnetic one gluon exchange interaction are perturbatively treated here to get the masses of $J^P={{1/2}}^{+}$ and $J^P={{3/2}}^{+}$ states. Accordingly, we obtain $\Xi^{++}_{cc}$ (3519, 3555), $\Xi^{+}_{cc}$ (3527, 3562) and $\Omega^{+}_{cc}$ (3648,3688) states of the $ccq$ $({1/2}^{+},{3/2}^{+})$ combinations. Our predictions are in accordance with the SELEX result for $\Xi^{++}_{cc}$ (3519) and other model predictions. Predictions of other properties of these $ccq$ systems will be presented in detail.