Vector meson production and the dipole picture in photon-hadron scattering.

摘要

This thesis extends and combines traditional methods of hadronic physics, quantum chromodynamics, and nuclear physics so that they may be consistently applied to particular new and interesting regimes of photon (lepton)-hadron scattering. High energy photo(lepto)-production from the deuteron offers a unique opportunity to experimentally test qualitative aspects of the Strong interaction, and to investigate the possibility of applying perturbative quantum chromodynamics (QCD) methods to nuclear physics. New experiments planned at Jefferson National Laboratory and Brookhaven National Laboratory may soon make this possible. Furthermore, there has been a steady increase in the amount of theoretical work being done in nonperturbative QCD, and in extending perturbative QCD methods to new kinematical regimes. As such, it is becoming increasingly important to understand the interplay of perturbative and nonperturbative effects in hadronic interactions, and to establish the boundary of the kinematic regions where traditional pQCD methods can be applied. This thesis elaborates on methods, namely the color dipole picture and the vector meson dominance model, for describing photon(lepton)-proton scattering, uses them to determine the regions of applicability of perturbative QCD. We give extensions of this analysis to the case of ultra-high energy photons which has possible applications in particle astrophysics. Also, we discuss the traditional Glauber-Gribov method used in deuteron scattering, and attempt to place it on a more formal footing. With the widespread use of the Glauber optical method in nuclear physics, it is important to establish where Glauber Theory is applicable and what modifications, if any, need to be made in order for it to be used in current applications. The long-term goal of this work is to combine a picture of photon (lepton)-nucleon scattering based on the Color Dipole Picture and hadronic fluctuations with the Glauber-Gribov model of deuteron scattering to obtain a complete description of photon (lepton)-nucleus interactions.