NNLL fit of the transverse-momentum-dependent distribution of unpolarised gluons to LHCb data on $J/\psi$-pair production
We perform the first fit of the unpolarised gluon transverse-momentum-dependent distribution $f_1^g$ up to next-to-next-to-leading-logarithmic accuracy to the double-differential distribution in the invariant mass and transverse momentum of the latest $J/\psi$-pair production LHCb data. We review previous attempts to d...