Speaker
Description
The finding of long rapidity range azimuthal correlations in small collision systems, pp and pA, at the LHC poses a crucial challenge for our understanding of hadronic and nuclear collisions at the highest available energies. In such small collisions systems the final state explanations standardly accepted in heavy ion collisions face conceptual problems and initial state alternatives have been explored. The Color Glass Condensate offers a weak coupling but non perturbative framework where the imprint on the final state of parton correlations in the wave functions of the incoming hadrons can be studied. Here we compute four gluon production in dilute-dense collisions in the CGC, considering only those contributions enhanced by the nuclear size but keeping all terms in the number of colours. We use the Wigner function approach to proceed analytically as far as possible and discuss its validity. We then analyse the four particle cumulant $c_2\{4\}$ and find it to be negative, thus providing a sensible second order Fourier coefficient.
