  One of the major challenges for the LHC will be to extract precise
information from hadronic final states in the presence of the large number of
additional soft pp collisions, pileup, that occur simultaneously with any hard
interaction in high luminosity runs. We propose a novel technique, based on jet
areas, that provides jet-by-jet corrections for pileup and underlying-event
effects. It is data driven, does not depend on Monte Carlo modelling and can be
used with any jet algorithm for which a jet area can be sensibly defined. We
illustrate its effectiveness for some key processes and find that it can be
applied also in the context of the Tevatron, low-luminosity LHC and LHC
heavy-ion collisions.

High Energy Physics - Phenomenology;High Energy Physics - Experiment