The implementation of the four-jet matrix elements in HERWIG and elsewhere

Abstract

The new version 6.1 of the HERWIG event generator allows one to simulate hadronic final states in electron-positron annihilations using the $O({\alpha }_s^2)$ partonic matrix elements (MEs) for $e^{+}{e}^{-}\to q\bar{q}gg$ and $e^{+}{e}^{-}\to q\bar{q}Q\bar{Q}$. The consequent phenomenology is discussed in the case of four-jet signatures of particular relevance to future electron-positron Linear Colliders (LCs), such as in Higgs boson searches. The new approach adopted in HERWIG is compared to the standard $O({\alpha }_s)$ description, as well as to other recently presented event generators also based on $e^{+}{e}^{-}\to 4$ parton MEs.

9 pages, latex, 4 figures (talk given at the 2nd ECFA/DESY Study on Physics and Detectors for a Linear Electron-Positron Collider, Padova, Italy, 4-8 May 2000): LC note number and reference added, one typo corrected