QCD Calculations by Numerical Integration

Abstract

Calculations of observables in Quantum Chromodynamics are typically performed using a method that combines numerical integrations over the momenta of final state particles with analytical integrations over the momenta of virtual particles. I discuss a method for performing all of the integrations numerically.

Figures (2)

• Figure 1: Two cuts of one of the Feynman diagrams that contribute to $e^+e^- \to {\it hadrons}$.
• Figure 2: Ratio $R$ of the order $\alpha_s^2$ contribution to the thrust distribution as calculated here to the same quantity as calculated by Kunszt and Nason, Ref. KN. The horizontal lines represent the expected result, 1, with an error estimate. The error bars on the computed points represent statistical errors. There is some correlation expected between neighboring points.