Jet Algorithms and the Underlying Event

Rick Field and David Stuart
Contribution to the Run II Workshop on QCD and Weak Boson Physics
Abstract
We examine and compare a variety of jet algorithms applied to charged particles (PT > 0.5 GeV, |eta| < 1) in proton-antiproton collisions at 1.8 TeV. In particular, we study how the jet algorithm affects the "size" and "impurity" of the leading charged particle jet. The "impurity" of a jet is the fraction of jet particles or fraction of the scalar PT sum arising from the underlying event. Any jet algorithm to be used in collider physics must be judged in the context of the collider environment (i.e. messy underlying event). From this point of view our analysis favors the kT algorithm approach over the midpoint method.

Postscript (PS) file of the entire paper (12 pages) or Adobe Acrobat (PDF) file of the just the figures (13 figs, 7 pages).

Rick Field - February 19, 2000