Double parton scattering as a source of quarkonia pairs in LHCb
  Recent results on production of $J/\psi$ pairs in LHCb initiated discussion on double parton scattering (DPS) contribution to this process, which is not yet elaborated well. In this short report $J/\psi \chi_c$ and $J/\psi \Upsilon$ modes are proposed for DPS studies. Estimations for $\Upsilon \Upsilon$ and $J/\psi \Upsilon$ production in LHCb are presented. 
Alexey Novoselov
hep-ph