Quarkonia in dimuon final states and exclusive dimuon decays at LHCb

Quarkonia cross-sections in hadron collisions are fundamental observables for understanding the production mechanisms. Exploiting the dimuon decay mode, the cross-sections for $J/\psi$ double $J/\psi, \psi$(2S) and Y(1S) production have been measured at LHCb [1] with $pp$ collisions at $\sqrt{s}$ = 7 TeV. Morever exclusive dimuon production, both resonant and non-resonant, has been studied and the cross-sections have been measured.