Pair double heavy diquark production in high energy proton-proton   collisions
  On the basis of perturbative QCD and relativistic quark model we calculate relativistic and bound state corrections in the production processes of a pair of double heavy diquarks. Relativistic factors in the production amplitude connected with the relative motion of heavy quarks and the transformation law of the bound state wave function to the reference frame of the moving S-wave diquark bound states are taken into account. For the gluon and quark propagators entering the amplitudes we use a truncated expansion in relative quark momenta up to the second order. Relativistic corrections to the quark-quark bound state wave functions in the rest frame are considered by means of the Breit-like potential. It turns out that the examined effects significantly decrease nonrelativistic cross sections. 
A.P. Martynenko (Samara State U. & Samara State Aerospace U.) and A.M.   Trunin (Samara State Aerospace U. & BLTP JINR)
hep-ph