[en] We use the techniques of an effective field theory for heavy quark systems to calculate inclusive lepton energy distributions in heavy meson decays. Our approach is patterned after the operator product expansion analysis of R in e⁺-e^- annihilation and deep inelastic electroproduction. We extend the idea of an operator product expansion to a situation in which we match the physics from a T-product in the high energy theory to a set of local operators in the low energy effective heavy quark field theory. In leading order we reproduce the results of the parton model, but we can also describe the corrections systematically. We are led to the rather surprising conclusion that there are no nonperturbative corrections of order m_bΛ_QCD to the average invariant mass-squared of the final hadronic state. (orig.)

[en] We consider the phenomenology of a technicolor model with softly broken flavor symmetries. First we explore the breaking of the large gauge symmetries of this model and use e⁺e^- scattering data to bound the VEV's responsible for the breaking. Next we examine the box diagrams responsible for quark and lepton masses in order to get a limit on the top quark mass. Finally, we consider contributions to FCNC effects arising from the extra gauge bosons and heavy fermions in this model. Because the flavor symmetry is softly broken, these are GIM-suppressed; they do, however, give additional limits on the model. (orig.)

[en] We consider the azimuthal angular dependence of the distribution of final-state hadrons in high energy lepton-proton scattering. The distribution displays an azimuthal asymmetry due to both perturbative and nonperturbative effects. At the large momentum transfers attainable, for example, at HERA we expect the perturbative effects to dominate and constitute a clear test of QCD. (orig.)

[en] We consider the azimuthal correlation of the final-state particles in charged weak-current processes. This correlation provides a test of perturbative quantum chromodynamics (QCD). The azimuthal asymmetry is large in the semi-inclusive processes in which we identify a final-state hadron, say, a charged pion compared to that in the inclusive processes in which we do not identify final-state particles and use only the calorimetric information. In semi-inclusive processes the azimuthal asymmetry is more conspicuous when the incident lepton is an antineutrino or a positron than when the incident lepton is a neutrino or an electron. We analyze all the possible charged weak-current processes and study the quantitative aspects of each process. We also compare this result to the ep scattering with a photon exchange. copyright 1997 The American Physical Society

[en] We consider the azimuthal angular dependence of the distribution of final-state hadrons in high-energy lepton-proton scattering. The distribution displays an azimuthal asymmetry due to both perturbative and nonperturbative effects. At the large momentum transfers attainable, for example, at the DESY ep collider HERA we expect the perturbative effects to dominate and constitute a clear test of QCD

[en] We study instanton effects on inclusive semileptonic b → u decay using the heavy quark effective field theory and the operator product expansion. The effect contributes not only to the hadronic matrix element but also to the coefficient functions in the operator product expansion. We find that the coefficient function is singular near the boundaries of the phase space. In order to use perturbative QCD reliably, it is necessary to introduce smearing near the boundary. However the instanton contribution to b → c decay seems negligibly small. (orig.)

[en] We study instanton effects on B → X_sγ decay using the heavy quark effective field theory and the operator product expansion. In the dilute gas approximation the effect is negligibly small. This is in contrast to the result of the instanton effect in inclusive semileptonic b → u decay but similar to the inclusive hadronic τ decay. We discuss the similarities and differences of the B → X_sγ decay compared to inclusive hadronic τ decay and semileptonic B decay. (orig.)

[en] The structure of hadronic jets depends not only on the dynamics of QCD but also on the details of the jet finding algorithm and the physical process in which the jet is produced. To study these effects in more detail we calculate the jet cross section and the internal jet structure in e⁺e^- annihilations and compare them to the results found in hadronic collisions using the same jet definition, the cone algorithm. The different structures of the overall events in the two cases are evident in the comparison. For a given cone size and jet energy, the distribution of energy inside the cone is more concentrated near the center for jets from e⁺e^- collisions than for jets from hadronic collisions. copyright 1997 The American Physical Society

[en] We investigate the effects of the Chern-Simons coupling on high-energy behavior in (2+1)-dimensional Chern-Simons QED with a four-Fermi interaction. Using the 1/N expansion we discuss the Chern-Simons effects on the critical four-Fermi coupling at O(1/N) and the β function around it. The high-energy behavior of Green's functions is also discussed. By explicit calculation, we find that the radiative correction to the Chern-Simons coupling vanishes at O(1/N) in the broken phase of the dynamical parity symmetry. We argue that no radiative corrections to the Chern-Simons term arise at higher orders in the 1/N expansion