The Underlying Event in Hadron-Hadron Collisions

摘要

We measured the ambient energy in jet events using data of the CDF experimentat center-of-mass energies of 1800 and 630 GeV by examining the transversemomentum of charged particles in a region of the detector far away from the twomost energetic jets in the event. The energy is compared to that found inminimum bias events. CDF data are compared to Monte Carlo predictions: neitherHerwig nor Pythia can reproduce the data in detail.