A study of high transverse energy events resulting from 400 GeV protons scattering from targets of hydrogen, carbon, aluminum, copper, tin, and lead has been performed with the E609 apparatus at Fermilab. Wire chambers and a highly segmented calorimeter detect secondary particles. The use of efficient jet collecting triggers and of a beam jet calorimeter have been originally applied to nuclear target studies in this thesis. A('(alpha)) scaling with hydrogen deviations is observed for E(,T) and planarity. The data provide evidence that A('(alpha)) scaling results from multiple scattering. Evidence for hadron jets is seen with a large solid angle calorimeter for all the targets when triggers requiring two high E(,T) single particles are employed. Jet cross-sections for nuclei are approximately determined herein. Jet event angular distributions possibly indicate that low and high transverse energy particles in jets from nuclei may result, in part, from different types of interactions.

A novel technique for measuring the vector polarization of scattered deuterons using the stripping reaction was developed and investigated in an experiment at the Clinton P. Anderson Meson Physics Facility (Los Alamos) measuring the vector polarization transfer parameters in the reaction p(' )p (--->) d(' )(pi)('+) at 800 MeV. The parameters P, K(,NN), and combinations of K(,SS) and K(,SL) and of K(,LS) and K(,LL) were measured at 5 angles to a statistical precision of less than 0.08 and with systematic uncertainties less than 0.05.

The time dependence of Ar('+)Xe (--->) ArXe('+) + hv(328nm) heteronuclear ion emission in Ar-Xe mixtures was measured following pulsed excitation by a low intensity, high energy electron beam. The time dependence was obtained at pressures of 120 to 3500 Torr and at temperatures ranging from 0 to 80 degrees C. The population of the upper ionic state of the transition is found to be governed by a dissociation-recombination reaction and is strongly quenched by formation of an unknown triatomic molecular ion of Ar and Xe. The measured dissociation, recombination, and quenching rate constants for Ar('+)Xe are (1 (+OR-) 0.3) x 10('-12) cm('3)/sec, (1.5 (+OR-) 0.5) x 10('-31) cm('6)/sec, and (5 (+OR-) 0.8) x 10('-31) cm('6)/sec, respectively. The radiative lifetime was determined to be 200 ns. Least squares fitting of the temperature dependent data yields an apparent activation energy of (TURN)0.14 eV.

The production of high transverse energy events in 400 GeV/c pp collisions triggered with a full azimuthal, large solid angle calorimeter is studied. A detailed comparison is made between the experimental data and a QCD Monte-Carlo which includes initial and final state gluon bremsstrahlung. Results on cross sections, energy flows, and event structures are presented for two different types of geometrically unbiased triggers. The characteristics of two and three jet events in the data and Monte-Carlo are also compared. We find that gluon bremsstrahlung effects as implemented in the Field-Fox-Wolfram Monte-Carlo are not sufficient to describe many features of both jetlike and non-jetlike events.

A full azimuth large-acceptance segmented calorimeter ((THETA)(,cm) ranging from 20(DEGREES) to 110(DEGREES)) and a beam calorimeter (covering a range (THETA)(,cm) < 20(DEGREES)) were used to study the production of large transverse energy events from (pi)('+)p, (pi)('-)p and pp interactions at 200 GeV. The (pi)p induced dijets were found, in agreement with earlier experiments, to deposit more energy in the forward direction and were more copiously produced at large E(,t) than the pp induced dijets. No dominant two-jet structure was found in the globally triggered data. Evidence has also been found for pion induced dijets with little or no forward energy flow. The rate and characteristics of these events are compatible with the predictions of Berger and Brodsky for higher-twist processes. No corresponding signal was seen in pp collisions.

The narrow gap III-V semiconductors, InAs/AlSb/GaSb and InSb, exhibit an array of extreme physical properties, from the lightest effective mass and largest nonparabolicity of III-V semiconductors to heterostructure conduction band offsets ranging from -0.15 to +2.0 eV. In this work, I present three spectroscopic techniques which exploit these unusual properties to provide new insight into the physics of these materials. First, my measurement of cyclotron resonance in InAs/AlSb and InSb/AlInSb quantum wells was the first spectroscopic application of a new laser, the THz quantum cascade laser. The physical properties mentioned above put these materials into an experimentally accessible range, and InAs's high room temperature mobility and low temperature carrier density enabled us to explore a large temperature range. Previous investigations of other materials in limited temperature ranges had suggested what we confirmed: the cyclotron resonance effective mass increases with temperature, contrary to theoretical expectations. Second, we applied time resolved cyclotron resonance to InSb quantum wells for the first time. Because of InSb's large effective g-factor and nonparabolicity, time resolved cyclotron resonance enabled us to monitor the carrier relaxation and recombination from each Landau- and Zeeman-quantized state directly in time. This unprecedented level of detail could be extended to longer times to probe spin-flip relaxation, a significant parasitic process in quantum computation. Finally, I measured intersubband absorption in narrow InAs/AlSb quantum wells with widths from 10.5 to 1.8 nm. I observed the highest energy intersubband resonance in InAs/AlSb quantum wells: 650 meV at 77 K in a 1.8 nm well. I also performed detailed measurements of the temperature dependence of intersubband absorption and confirmed the correlation between the integrated intensity of intersubband absorption and the carrier distribution inferred from Shubnikov-de Haas and Hall measurements. Because of InAs/AlSb intersubband transitions' large accessible energy and temperature robustness, they are ideal candidates for resonant nonlinear optics. In particular, I discuss the potential of InAs/AlSb double quantum wells as a compact, room temperature, and coherent THz source. Such a source could revolutionize chemical sensing by providing convenient access to the strong fundamental vibrational fingerprints which all molecules have in the THz, potentially transforming applications from medicine to the military.

The production of charmonium states J/$ Psi$ and $ Psi sp prime$ was measured at 300 GeV/c with $ pi sp{ pm}$, p, and p beams on a lithium target. The cross sections were determined by analyzing a fraction (10%) of the data recorded by the experiment E705 at Fermilab. The data acquisition took place at the High Intensity Laboratory located on the "Proton West" beam line, and extended over a period of nine month during 1987-1988. / The efficiencies for the different detector components of the E705 spectrometer were measured, and the global acceptance was determined. The measured absolute cross sections for J/$ Psi$ and $ Psi sp prime$ are consistent with the measurements obtained in other experiments. The differential cross section for J/$ Psi$ production was measured for the kinematical variables X$ sb{ rm f}$, P$ sb{ rm t}$, and for the J/$ Psi$ decay angles. The distributions obtained are compared with the distributions measured at other energies by previous experiments.

The possibility of observing CP (or T) violation from the leptonic sector of the Standard Model in $e sp pm p$ scattering at HERA is investigated. Neglecting fermion masses, an effective-Lagrangian approach is used to compute model-independent predictions of an eventual CP-breaking asymmetry. The asymmetry is defined as the difference between the number of final electrons (for charged-current events), or jets (for neutral-current events), that leave the detector to the left and right of the plane defined by the axis of the incoming electron beam and its direction of polarization. It is found that HERA should be reasonably sensitive to CP-violation in the case of charged-current $e sp- p$ scattering events.

One of the unique features of the E814 experimental setup at the BNL-AGS, is its nearly 4$ pi$ calorimetry. Calorimeters, however, do not provide information on the nature of particles and their multiplicity. Particle identification is important to understand the expansion phase of the hot nuclear matter produced in relativistic heavy ion collisions. In the present 814 experiment the charged particle multiplicity is measured at forward angles only, by a Si pad detector. The addition of a similar Si detector in the target rapidity region, overlapping the Target Calorimeter, is being considered. Initial calculations have shown a possibility of particle identification by using the signals from a silicon detector and from the highly segmented Target Calorimeter. In this thesis, the potential for particle identification of an upgraded silicon multiplicity detector at target rapidity is evaluated using a silicon surface barrier detector and part of the Target Calorimeter. The measured response is compared to the predictions of the event generator HIJET followed by complete tracking using the code GEANT.

The order $G sb{F}m sbsp{t}{2}$ electro-weak corrections to the decay $t to bW sp+$ are calculated, arising essentially from virtual radiation of the Higgs boson. For large $m sb{t}$ these represent the dominant effect serving to shift the top lifetime from its tree level value. In practice, for $m sb{t}$ $<$ 240 $GeV$ these corrections are typically 0.1%. A comparison with recent calculations of the complete electro-weak and strong effects is made. / Several contributions to the branching ratio for the inclusive decay $ Upsilon to J/ psi X$ are calculated using perturbative Q.C.D. to lowest order in the relative quark momentum and the strong coupling $ alpha sb{s}$. In addition to the direct transition, decay to J/$ psi$ through the states $ psi sp prime$ and $ chi sb1$ is also considered. The following results are obtained: $Br( Upsilon to psi sp prime X$) = (0.26 $ pm$ 0.13) $ times$ 10$ sp{-3}$, $Br( Upsilon to chi sb1 X$) $ le$ 0.17 $ times$ 10$ sp{-3}$, and $Br( Upsilon to J/ psi X$) = (0.44 $ pm$ 0.15) $ times$ 10$ sp{-3}$. The latter may just be consistent with the experimental result (1.1 $ pm$ 0.4 $ pm$ 0.2) $ times$ 10$ sp{-3}$ where the first error is statistical and the second systematic.