Data Selection and Reconstruction

The selection and reconstruction of ${\rm q}\bar{\rm q}\ell\bar{\nu}_{\ell}$ events consists of two basic phases. Firstly the selection of ${\rm q}\bar{\rm q}\ell\bar{\nu}_{\ell}$ events is made using the WW package [92], a set of routines developed by OPAL and designed for the study of W-pair events. This selection is the same as used by OPAL to measure the total W-pair production cross-section [66] and therefore does not require completely reconstructed events.

For the measurement of TGCs and the study of W decays, the tracks in the event need to be more cleanly reconstructed. The second phase of selection and reconstruction involves taking the events selected by the previous process and performing kinematic fits on them, this then rejects any poorly reconstructed events. This process is achieved using the WV package [93], which is a set of routines designed to complement the WW package.