Measurement of energy flow at large pseudorapidities in pp collisions at √s = 0:9 and 7 TeV

The energy ow, dE=dη, is studied at large pseudorapidities in proton-proton collisions at the LHC, for centre-of-mass energies of 0.9 and 7TeV. The measurements are made using the CMS detector in the pseudorapidity range 3:15 < |η| < 4:9, for both minimum-bias events and events with at least two high-momentum jets. The data are compared to various pp Monte Carlo event generators whose theoretical models and input parameter values are sensitive to the energy-ow measurements. Inclusion of multipleparton interactions in the Monte Carlo event generators is found to improve the description of the energy-ow measurements.