Hadronic production of heavy mesons in perturbative QCD
  In the framework of perturbative QCD in the fourth order over the $\alpha_s$ coupling constant for the production of two pairs of quarks and in the model of weak binding of the quarks into meson, the analysis of the hadronic production of mesons, containing $b$-quark, is performed, and a minimal transverse momentum is determined, so that at the momenta greater than the found one, the meson differential spectrum can be reliably described in the model of factorization of the hard $b$-quark production and the subsequent fragmentation into the mesons. At low transverse momenta of the meson, nonfragmentational contributions are essential. They are determined by the complete set of QCD diagrams in the given order over $\alpha_s$, so that the latters result in the effect of destructive interference with the diagrams of fragmentation at $z=2E/\sqrt{s}$ close to $1$. 
A.V.Berezhnoy, V.V.Kiselev, A.K.Likhoded