Problem of color excitation and certain renormalization effects in unified gauge theories

In this thesis we present a study of the possiblity of the production of color-nonsinglet hadronic states in electromagnetic, charged- and neutral-current deep inelastic scatterings within the framework of Pati-Salam theory. As is well known, above some threshold energy the nucleon structure functions should receive contributions from the production of color-octet states corresponding to the excitations of the color degree of freedom of quarks and gluons in this theory. This is expected to cause a rise especially in the nucleon structure functions for this theory within the framework of the parton model. Next we calculate the amount of the expected rises incorporating certain corrections to earlier analyses. We show in Chapter 4 that quark-parton contributions to two-photon processes (i.e. e-e+ → e-e+ q anti q) for double-tagged events can hardly distinguish between gauge integer and fractionally charged quarks. This is contrary to common claims. In Chapter 5, we find that renormalization effects for the ΔB = 2, ΔL = 0 six-quark operators leading to neutron-antineutron (n-anti n) oscillations can give rise to a reduction in the oscillation period by a factor of approx. 2 to 10. Finally in Chapter 6, we undertake the problem of finding patterns of spontaneous symmetry breaking (SSB) in [SU(16)]/sup P/ allowing the coexistence of (n-anti n) oscillation together with proton decay. We show by solving the renormalization-group evolution equations for the gauge coupling constants in a specific SSB pattern that for p greater than or equal to 3 this may indeed be the case