A Study of Proton Photoproduction on Carbon

[摘要] The work presented in this thesis describes an experimental study of the photodisintegration of the carbon-12 nucleus at intermediate photon energies. This is the first in a series of experiments by Glasgow University in collaboration with Edinburgh and Tubingen Universities at the tagged photon facility at MAMI-B at the Mainz Institut fur Kernphysik. Two nucleon emission in the energy region between 50 and 150MeV has already been studied extensively, the results indicating that photons in this energy range are absorbed by a correlated nucleon pair, the quasi-deuteron mechanism. However, immediately above these energies the photon can be absorbed by single nucleon forming a Delta(1232) resonance which subsequently de-excites via quasi-free pion production. Previous experiments in the Delta resonance region have suffered from poor resolution and it is therefore the aim of the present experiment to study these competing mechanisms in detail. It is anticipated that such a study will yield information about meson exchange currents, short range correlations and A propagation in nuclear matter. Photons were produced by Bremsstrahlung on a metal foil using 855MeV electrons extracted from MAMI-B and their energies were calculated by momentum analysing the residual electrons using the Glasgow tagging spectrometer. The photons impinge on a natural graphite target and the momenta of the photoreaction products are measured by two new detector arrays PIP and TOF. PIP is a large solid angle DeltaE-DeltaE-E telescope which was placed at 90

[发布机构] University:University of Glasgow

[关键词] Nuclear physics and radiation, High energy physics