Spin density matrix element extraction for the p°vector meson on hydrogen and deuterium targets at HERMES

The HERMES experiment in Hamburg, Germany, consists of a large forward spectrometer which studies various physics processes related to the nucleon and its internal structure. The main focus of the analysis presented in this thesis is based on the angular decay distributions of the decay products of the ρ0 vector meson. By examining the angular decay of the outgoing decay products the Spin Density Matrix Elements (SDMEs) for the ρ 0 can be determined. The extraction of the ρ0 data sample from the raw HERMES output data is explained and the method used to extract exclusive, diffractive ρ0s is given. The analysis procedure and the method used to analyse the data samples is then explained with consideration given to the description of the method used to extract the spin density matrix elements. In the autumn of 2005 a new detector known as the Recoil Detector will be commissioned in the front region of the HERMES experiment. The Recoil Detector will advance the analysis presented in this thesis in some regards, ie the improved t-resolution at low t which will improve exclusive measurements including vector meson production. Several contributions to the Recoil Detector are presented in detail. In particular the research of the HELIX128-3.0 readout chip and its development towards the final readout of the silicon detector and the integration of the Recoil Detector into the Hermes Monte Carlo