Gluon splitting in a shockwave

Understand

The study of azimuthal correlations in particle production at forward rapidities in proton-nucleus collisions provides direct information about high gluon density effects, like gluon saturation, in the nuclear wavefunction.

• In the kinematical conditions for proton-lead collisions at the LHC, the forward di-hadron production is dominated by partonic processes in which a gluon from the proton splits into a pair of gluons, while undergoing multiple scattering off the dense gluon system in the nucleus.
• We compute the corresponding cross-section using the Colour Glass Condensate effective theory, which enables us to include the effects of multiple scattering and gluon saturation in the leading logarithmic approximation at high energy.
• This opens the way towards systematic studies of angular correlations in two-gluon production, similar to previous studies for quark-gluon production in the literature.