Elastic J Photoproduction and the Detection and Triggering of Muons at Low W p using the H Detector

Synopsis The electron-proton colliding beam facility HERA consists of two independent accelerators designed to store 820 GeV protons and 27.5 GeV electrons. The two b e a m s circulate in opposite directions in an underground tunnel, 6.3 km in length. At t wo interaction points the beams are collided head on and some of the highest energy ep collisions ever attained are observed. The H1 detector is situated at one of these interaction points and observes the reaction products from these collisions. This report rstly discusses brieey the physics potential that HERA has to ooer and follows this by a description of the H1 detector at HERA. Particular emphasis is made on the subdetectors which can be found in thèforward direction' (the direction of the proton beam) which i s d e n e d b y the angular region 7 < < < 25. The detailed studies presented here concentrate on the detection and triggering of muons within this region with the aim to calculate the elastic cross-section for the production of J= mesons. Muons are detected in the forward region by the Forward Tracking Detector (FTD), the instrumented iron (which surrounds the whole of the H1 experiment), and the Forward Muon Detector (FMD). Analyses have been completed on the correlation of the momenta measured in the FTD, CTD and the FMD for 1995 and 1996 data and signiicant diierences have been found which can be attributed to problems associated with vertex tted FTD tracks. Additionally, a preliminary determination of the eciency and acceptance of the Forward Muon Trigger (FMT) and FMD have been made. These are both important steps towards analysing forward muon producing processes and ultimately other forward processes. Cross-section measurements for the p! JJpprocess have been made by detecting the products of the J= decaying to + ;. The measurements give a n indication of the W p dependence of the cross-section extended to W p values lower than measured previously by H 1. Acknowledgements I w ould like to thank all the people who have helped me to complete this Phd. I would like to thank Dr Ian Kenyon my supervisor, Professor John Dowell and Dr John Garvey for their help. A speciaìThank you!' also goes to Dr Lee West who displayed huge amounts of patience on many occasions. As I spent a considerable amount o f m y t i m e a …