The Design of the ZEUS regional first level trigger box and associated trigger studies

The design of electronics suitable for fast event selection in the first level of the ZEUS trigger has been studied using a Monte Carlo simulation technique. It was found that integrating tracking information from two detectors (the Central Tracking Detector and the Forward Tracking Detector) at this level was both possible and beneficial. It was shown that this method improved efficiency of acceptance of DIS events of interest while enhancing rejection of background. The performance of this part of the trigger was investigated for other physics: heavy quark pair production and J/ events produced via bosongluon fusion. A method of investigating the kinematic dependency of the Central Tracking Detector first level trigger in such a way as to reduce computer resources required to acceptable levels was devised and implemented.