Estimate of the hadronic production of the doubly charmed baryon Ξcc in the general-mass variable-flavor-number scheme

To try to understand the experimental observation of SELEX Collaboration and to check the existent results in literature, we have done a theoretical investigation on hadronic production of the doubly charmed baryon Xi(cc) (Xi(++)(cc) or Xi(+)(cc)) under the general-mass variable-flavor-number (GM-VFN) scheme. A similar study of the production at LHC and TEVATRON is also performed. The production here is realized via production of a binding diquark either (cc)[S-3(1)]((3) over bar) (in configuration S-wave and in color (3) over bar) or (cc)[S-1(0)](6) (in configuration S-wave and in color 6) instead of only the diquark (cc)[S-3(1)]((3) over bar) is considered. Numerical results show that the production via each configuration of the diquark is comparable at LHC and TEVATRON under the condition that the NRQCD matrix elements relevant to the diquark production are assumed approximately to be equal to each other; and the contributions from collision of a so-called extrinsic charm and a gluon inside the colliding hadrons are comparable with, or even greater than, those from the so-called gluon-gluon fusion, especially, in the region of small transverse-momentum p(t). We also note that due to the contributions from the extrinsic charm, the theoretical prediction on the production of the baryon Xi(cc) is raised by one order in comparison with the existent predictions almost.