ИСТИНА

The energy flow, dE/dEta, is studied with the focus on the region close to the beam rapidity using the CMS forward detectors and in particular the CASTOR calorimeter (5.2 < eta < 6.6). The forward directed particle production is probing very low-x parton momentum fractions of the nucleus structure. We are looking for evidence of multi-parton-interactions, saturation effects, and the underlying event. Both proton-proton collisions at different center of mass energies as well as PbPb collisions are analysed and presented here. The performance of event generators, including SIBYLL, EPOS and QGSJetII, are tested against these data. QCD saturation and hadron production as well as energy flow in the forward region at LHC provide important constraints on the interpretation of ultra-high energy cosmic rays with these models.