One of the biggest challenges in Chemical Dynamics is describing the behavior of complex systems accurately. Classical MD simulations have evolved to a point where calculations involving thousands of atoms are routinely carried out. Capturing coherence, tunneling and other such quantum effects for these systems, however, has proven considerably harder. Semiclassical methods such as the Initial Value Representation (SC-IVR) provide a practical way to include quantum effects while still utilizing only classical trajectory information. For smaller systems, this method has been proven to be most effective, encouraging the hope that it can be extended to deal with a large number of degrees of freedom. Several variations upon the original idea of the SCIVR have been developed to help make these larger calculations more tractable; these range from the simplest, classical limit form, the Linearized IVR (LSC-IVR) to the quantum limit form, the Exact Forward-Backward version (EFB-IVR). In this thesis a method to tune between these limits is described which allows us to choose exactly which degrees of freedom we wish to treat in a more quantum mechanical fashion and to what extent. This formulation is called the Tuning IVR (TIVR). We further describe methodology being developed to evaluate the prefactor …

The author presents measurements of radiative B meson decays to the final states K{sub s}{sup 0}{pi}{sup 0}{gamma} and K{phi}{gamma} based on data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. In a data sample of 467 million B{bar B} pairs, the time-dependent CP asymmetry in B{sup 0} {yields} K{sub s}{sup 0}{pi}{sup 0}{gamma} decays is measured in two regions of K{sub s}{sup 0}-{pi}{sup 0} invariant mass. In the K* region, 0.8 < m(K{sub s}{sup 0}{pi}{sup 0}) < 1.0 GeV/c{sup 2}, we find S{sub K*{gamma}} = -0.03 {+-} 0.29 {+-} 0.03 and C{sub K*{gamma}} = -0.14 {+-} 0.16 {+-} 0.03; in the range 1.1 < m(K{sub s}{sup 0}{pi}{sup 0}) < 1.8 GeV/c{sup 2}, they find S{sub K{sub s}{sup 0}{pi}{sup 0}{gamma}} = -0.78 {+-} 0.59 {+-} 0.09 and C{sub K{sub s}{sup 0}{pi}{sup 0}{gamma}} = -0.36 {+-} 0.33 {+-} 0.04. With a sample of 228 million B{bar B} pairs they measure the branching fraction {Beta}(B{sup +} {yields} K{sup +}{phi}{gamma}) = (3.5 {+-} 0.6 {+-} 0.4) x 10{sup -6} and set the limit {Beta}(B{sup 0} {yields} K{sup 0}{phi}{gamma}) < 2.7 x 10{sup -6} at 90% confidence level. The direct CP asymmetry in B{sup +} {yields} …

In this thesis work we have measured the following upper limits at 90% of confidence level, for B meson decays (in units of 10{sup -6}), using a statistics of 465.0 x 10{sup 6} B{bar B} pairs: {Beta}(B{sup 0} {yields} {eta}K{sup 0}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{eta}) < 1.4 {Beta}(B{sup 0} {yields} {eta}{prime}{eta}{prime}) < 2.1 {Beta}(B{sup 0} {yields} {eta}{phi}) < 0.52 {Beta}(B{sup 0} {yields} {eta}{omega}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{prime}{phi}) < 1.2 {Beta}(B{sup 0} {yields} {eta}{prime}{omega}) < 1.7 We have no observation of any decay mode, statistical significance for our measurements is in the range 1.3-3.5 standard deviation. We have a 3.5{sigma} evidence for B {yields} {eta}{omega} and a 3.1 {sigma} evidence for B {yields} {eta}{prime}{omega}. The absence of observation of the B{sup 0} {yields} {eta}K{sup 0} open an issue related to the large difference compared to the charged mode B{sup +} {yields} {eta}K{sup +} branching fraction, which is measured to be 3.7 {+-} 0.4 {+-} 0.1 [118]. Our results represent substantial improvements of the previous ones [109, 110, 111] and are consistent with theoretical predictions. All these results were presented at Flavor Physics and CP Violation (FPCP) 2008 Conference, that took place in Taipei, Taiwan. They will be …

This dissertation discusses a data collection experiment within the Actinide Isomer Identification project (AID). The AID project is the investigation of an active interrogation technique that utilizes nuclear isomer production, with the goal of assisting in the interdiction of illicit nuclear materials. In an attempt to find and characterize isomers belonging to 235U and its fission fragments, a 232Th target was bombarded with a monoenergetic 6Li ion beam, operating at 45 MeV.

A unique approach to crack-free joining of heterogeneous ceramics is demonstrated by the use of sialon polytypoids as Functionally Graded Materials (FGM) as defined by the phase diagram in the system, Si3N4-Al2O3. Polytypoids in the Al2O3-Si3N4 system offer a path to compatibility for such heterogeneous ceramics. The first part of the dissertation describes successful hot press sintering of multilayered FGM's with 20 layers of thickness 500 mm each. Transmission Electron Microscopy was used to identify the polytypoids at the interfaces of different areas of the joint. It has been found that the 15R polytypoid was formed in the Al2O3-contained layers and the 12H polytypoid was formed in the Si3N4-contained layers. The second part of the dissertation discusses the mechanical properties of these polytypoidally joined Si3N4-Al2O3. The thermal stresses of this FGM junction were analyzed using a finite element analysis program (FEAP) taking into account both coefficient of thermal expansion (CTE) and modulus variations. From this analysis, the result showed a dramatic decrease in radial, axial and hoop stresses as the FGM changes from three layers to 20 graded layers. Scaling was considered, showing that the graded transition layer should constitute about 75 percent or more of the total sample thickness …

We have demonstrated that a bulk absorber coupled to a TES can serve as a good gamma-ray spectrometer. Our measured energy resolution of 70 eV at 60 keV is among the best measurements in this field. We have also shown excellent agreement between the noise predictions and measured noise. Despite this good result, we noted that our detector design has shortcomings with a low count rate and vulnerabilities with the linearity of energy response. We addressed these issues by implementation of an active negative feedback bias. We demonstrated the effects of active bias such as additional pulse shortening, reduction of TES change in temperature during a pulse, and linearization of energy response at low energy. Linearization at higher energy is possible with optimized heat capacities and thermal conductivities of the microcalorimeter. However, the current fabrication process has low control and repeatability over the thermal properties. Thus, optimization of the detector performance is difficult until the fabrication process is improved. Currently, several efforts are underway to better control the fabrication of our gamma-ray spectrometers. We are developing a full-wafer process to produce TES films. We are investigating the thermal conductivity and surface roughness of thicker SiN membranes. We are exploring alternative …