An Angular Correlation Test of Time Reversal Invariance

Gamma-ray angular correlation experiment of time reversal invarianc

Nutrient chemistry of a large, deep lake in subarctic Alaska

Project Officer Eldor W. Schallock Assessment and Criteria Development Division Corvallis Environmental Research Laboratory Corvallis, Oregon 97330;Corvallis Environmental Research Laboratory Office of Research and Development U. S. Environmental Protection Agency Corvallis, Oregon 97330; R800276The primary objective of this project was to assess the state of the water quality of Harding Lake, and to attempt to predict the effects of future development within its watershed. Since the major effect of degradation of water quality due to human activity is the promotion of nuisance growths of plants, the major emphasis was placed on measurements of plant growth and concentrations of the major nutrients they require. Planktonic algal growth was found to be low, below 95.6 gm/m2/year, and the growth of submerged rooted plants was found to be relatively less important at approximately 1.35 gm/m2/year. Measurements of the growth of attached algae were not conducted, therefore the relative importance of their growth is currently unknown. A model for predicting the effect of future real estate development in the watershed was modified and applied to this lake. This model adequately describes current water quality conditions, and is assumed to have some predictive ability, but several cautions concerning application of this model to Harding Lake are discussed. A secondary objective was to study the thermal regime of a deep subarctic lake. Intensive water temperature measurements were made throughout one year and less intensive measurements were conducted during two additional years. The possibility that this lake may occasionally stratify thermally under the ice and not mix completely in the spring was discovered. The implications of this possibility are discussed for management of subarctic lakes. Hydrologic and energy budgets of this lake are attempted; the annual heat budget is estimated at 1.96 x 104 ± 1.7 x 103 cal/cm2. The results of a study of domestic water supply and waste disposal alternatives in the watershed, and the potential for enteric bacterial contamination of the lake water are presented. Limited work on the zooplankton, fishes, and benthic macroinvertebrates of this lake is also presented

Angular Correlation of Cascade Gamma Rays in 94nb

Angular correlation of cascade gamma rays in niobiu

Hadron mass corrections in semi-inclusive deep-inelastic scattering

The spin-dependent cross sections for semi-inclusive lepton-nucleon scattering are derived in the framework of collinear factorization, including the effects of masses of the target and produced hadron at finite momentum transfer squared Q^2. At leading order the cross sections factorize into products of parton distribution and fragmentation functions evaluated in terms of new, mass-dependent scaling variables. The size of the hadron mass corrections is estimated at kinematics relevant for future semi-inclusive deep-inelastic scattering experiments.Comment: 28 pages, 12 figures, published versio

Removal of monocular interactions equates rivalry behavior for monocular, binocular, and stimulus rivalries

When the two eyes are presented with conflicting stimuli, perception starts to fluctuate over time (i.e., binocular rivalry). A similar fluctuation occurs when two patterns are presented to a single eye (i.e., monocular rivalry), or when they are swapped rapidly and repeatedly between the eyes (i.e., stimulus rivalry). Although all these cases lead to rivalry, in quantitative terms these modes of rivalry are generally found to differ significantly. We studied these different modes of rivalry with identical intermittently shown stimuli while varying the temporal layout of stimulation. We show that the quantitative differences between the modes of rivalry are caused by the presence of monocular interactions between the rivaling patterns; the introduction of a blank period just before a stimulus swap changed the number of rivalry reports to the extent that monocular and stimulus rivalries were inducible over ranges of spatial frequency content and contrast values that were nearly identical to binocular rivalry. Moreover when monocular interactions did not occur the perceptual dynamics of monocular, binocular, and stimulus rivalries were statistically indistinguishable. This range of identical behavior exhibited a monocular (∼50 ms) and a binocular (∼350 ms) limit. We argue that a common binocular, or pattern-based, mechanism determines the temporal constraints for these modes of rivalry

Physics Potential of Very Intense Conventional Neutrino Beams

The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters and measure or severely constrain the parameter connecting the atmospheric and solar realms. It is also shown that a very large water detector could eventually observe leptonic CP violation. The reach of such an experiment to the neutrino mixing parameters would lie in-between the next generation of neutrino experiments (MINOS, OPERA, etc) and a future neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice, March, 200

Optimizing propagating spin wave spectroscopy

The frequency difference between two oppositely propagating spin waves can be used to probe several interesting magnetic properties, such as the Dzyaloshinkii-Moriya interaction (DMI). Propagating spin wave spectroscopy is a technique that is very sensitive to this frequency difference. Here we show several elements that are important to optimize devices for such a measurement. We demonstrate that for wide magnetic strips there is a need for de-embedding. Additionally, for these wide strips there is a large parasitic antenna-antenna coupling that obfuscates any spin wave transmission signal, which is remedied by moving to smaller strips. The conventional antenna design excites spin waves with two different wave vectors. As the magnetic layers become thinner, the resulting resonances move closer together and become very difficult to disentangle. In the last part we therefore propose and verify a new antenna design that excites spin waves with only one wave vector. We suggest to use this antenna design to measure the DMI in thin magnetic layers.Comment: 12 pages, 4 figure

Physics Potential of the SPL Super Beam

Performances of a neutrino beam generated by the CERN SPL proton driver are computed considering a 440 kton water Cerenkov detector at 130 km from the target. $\theta_{13}$ sensitivity down to $1.2^\circ$ and a $\delta$ sensitivity comparable to a Neutrino Factory, for $\theta_{13} \geq 3^\circ$, are within the reach of such a project.Comment: Invited talk at the Nufact02 Workshop, Imperial College of Science, Technology and Medicine, London, July 200