Production of quarkonia and doubly heavy baryons in $pp$-collisions with   duality approach
  In present work we discuss the production of heavy quarkonia and diquarks in $pp$-interactions. The aim is to take into account the production of bound states of quarks originating from independent parton scatterings. This production is regulated by constraints on the invariant mass of constituents. Such an approach leads to larger value of the diquark production cross section than traditional consideration in single parton scattering. This production mechanism of doubly heavy baryons can sooner be verified by modern experiments (e.g. LHCb). We also discuss related contributions to double and associated quarkonium production. 
V.V. Kiselev, A.A. Novoselov and E.R. Tagiev
hep-ph