# QCD corrections to $e^+e^-\rightarrow 4$ jets

Abstract : This thesis deals with perturbative QCD-corrections to four-jet production in electron-positron annihilation. The one-loop corrections to the subprocess $e^+ e^- \rightarrow q \bar{q} Q \bar{Q}$ are calculated, using modern techniques in order to calculate the one-loop amplitudes efficiently. These techniques include colour decomposition, the spinor helicity method and decompositions inspired by supersymmetry. The cut technique and the factorization in collinear limits are used to constrain the analytic form of the amplitudes. In a second step the virtual corrections from $e^+ e^- \rightarrow q \bar{q} Q \bar{Q}$ and $e^+ e^- \rightarrow q g g \bar{q}$ are implemented together with the corresponding real emission parts into a numerical program. The cancelation of the infrared singularities is based on the dipole formalism. Numerical values are given for the total cross-section, the $D$-parameter and the jet broadening variable
Keywords :
Document type :
Theses

https://tel.archives-ouvertes.fr/tel-00000814
Contributor : Marc Gingold <>
Submitted on : Friday, October 12, 2001 - 12:00:00 AM
Last modification on : Wednesday, September 12, 2018 - 2:13:57 PM
Long-term archiving on: : Tuesday, September 11, 2012 - 1:00:26 PM

### Identifiers

• HAL Id : tel-00000814, version 1

### Citation

Stefan Weinzierl. QCD corrections to $e^+e^-\rightarrow 4$ jets. Physique mathématique [math-ph]. Université Paris Sud - Paris XI, 1998. Français. ⟨tel-00000814⟩

Record views