First estimates of the $B_c$ wave function from the data on the $B_c$ production cross section

In the framework of perturbative QCD and nonrelativistic bound state formalism, we calculate the production of $B_c$ and $B_c^{\ast }$ mesons at the conditions of the CDF and LHCb experiments. We derive first estimations for the $B_c$ wave function from a comparison with the available data.