QCD AT THE TEVATRON: RECENT QCD RESULTS FROM THE CDF AND D0 EXPERIMENTS

摘要

Quantum Chromodynamics (QCD) is the SU(3) gauge theory of colored quarks and self interacting, colored gluons which describes the strong interaction within the standard model of elementary particles. The coupling constant as depends on momentum transfer: the theory is perturbative at high momentum transfers, but non-perturbative and strongly coupled for soft processes (leading to quark confinement and to the existence of hadrons). For hadron colliders, QCD processes have the advantage of large cross sections and essentially no backgrounds; but the strong final state interactions lead to the quarks and gluons of the underlying theory appearing as jets of hadrons in the detector. Jets suffer from ambiguities of reconstruction (merging and splitting) and uncertainties in the energy scale. Where cross sections permit, some of these systematic problems may be avoided by using W and Z bosons and photons in the Anal state.