e^+ (Anti)Quark Scattering in the Presence of the Anomalous HERA Positron-Jet Event Phenomenon

We discuss the leptoquark interpretation of the anomalous HERA positron-jet events in the context of the YFS exponentiated Monte Carlo event generator treatment of the attendant multiple photon radiative effects for both the would-be signal and the SM background, wherein finite-$p_T$ photon effects are properly taken into account and wherein infrared singularities are cancelled to all orders in $\alpha$. We show that H1 and ZEUS data are consistent with such an interpretation for a leptoquark coupling $\lesssim 0.3g_W$, mass $\sim 200$ GeV, and width $\lesssim 2$GeV. Possible future tests are proposed.Comment: 9 pages, 3 figures, Latex and bbl file

Development of the elevation drive assembly for orbiting solar observatory I (EYE)

The requirements for pointing accuracy, friction, and power for the elevation drive assembly of an orbiting space observatory are discussed briefly. A description of the components making up the assembly is presented. Special features requiring development testing prior to unit fabrication are more fully described together with a review of the test programs conducted and results obtained

Holographic photography of high velocity particles

Fourier transform hologram camera increases the velocity range for holography by a factor of 10 to 1000. Two different optical systems, using a triangular arrangement of beam splitters and a mirror to illuminate the object from two directions, are investigated

The effects of acceleration stress on human workload and manual control

The effects of +Gz stress on operator task performance and workload were assessed. Subjects were presented a two dimensional maze and were required to solve it as rapidly as possible (by moving a light dot through it via a trim switch on a control stick) while under G-stress at levels from +1 Gz to +6 Gz. The G-stress was provided by a human centrifuge. The effects of this stress were assessed by two techniques; (1) objective performance measures on the primary maze-solving task, and (2) subjective workload measures obtained using the subjective workload assessment technique (SWAT). It was found that while neither moderate (+3 Gz) nor high (+5 Gz and +6 Gz) levels of G-stress affected maze solving performance, the high G levels did increase significantly the subjective workload of the maze task

Coherent Exclusive Exponentiation for Precision Monte Carlo Calculations of Fermion Pair Production / Precision Predictions for (Un)stable W+W- Pairs

We present the new Coherent Exclusive Exponentiation (CEEX), in comparison to the older Exclusive Exponentiation (EEX) and the semi-analytical Inclusive Exponentiation (IEX), for the process e+e- -> f-bar f + n(gamma), f=mu,tau,d,u,s,c,b, with validity for centre of mass energies from tau lepton threshold to 1 TeV. We analyse 2f numerical results at the Z-peak, 189 GeV and 500 GeV. We also present precision calculations of the signal processes e+e- -> 4f in which the double resonant W+W- intermediate state occurs using our YFSWW3-1.14 MC. Sample 4f Monte Carlo data are explicitly illustrated in comparison to the literature at LEP2 energies. These comparisons show that a TU for the signal process cross section of 0.4 percent is valid for the LEP2 200 GeV energy. LC energy results are also shown.Comment: 5 pages, 4 figures, Presented at ICHEP200

Psychological Issues in Online Adaptive Task Allocation

Adaptive aiding is an idea that offers potential for improvement over many current approaches to aiding in human-computer systems. The expected return of tailoring the system to fit the user could be in the form of improved system performance and/or increased user satisfaction. Issues such as the manner in which information is shared between human and computer, the appropriate division of labor between them, and the level of autonomy of the aid are explored. A simulated visual search task was developed. Subjects are required to identify targets in a moving display while performing a compensatory sub-critical tracking task. By manipulating characteristics of the situation such as imposed task-related workload and effort required to communicate with the computer, it is possible to create conditions in which interaction with the computer would be more or less desirable. The results of preliminary research using this experimental scenario are presented, and future directions for this research effort are discussed

Precision W-pair physics with the YFSWW3 and KoralW Monte Carlos

We present the recent developments in the precision studies of W-pair and single-W processes in e+e- collisions achieved with the help of the KoralW and YFSWW3 Monte Carlo generators. We focus on the theoretical precision of the measurements of M_W and anomalous couplings on the example of lambda coupling. We present the mechanism of running these two independent codes in the form of one Concurrent Monte Carlo code. We describe also the extensions of KoralW necessary to emulate the kinematical region of single-W process.Comment: Talk given by M. Skrzypek at 6th International Symposium on Radiative Corrections, 8-13 September 2002, Kloster Banz, German

W-Pair Production with YFSWW/KoralW

A theoretical description of W-pair production in terms of two complementary Monte Carlo event generators YFSWWand KoralW is presented. The way to combine the results of these two programs in order to get precise predictions for WW physics at LEP2 and LC energies is discussed.Comment: LateX file, 6 pages, conference contributio

Feasibility Study of Velocity Synchronized Fourier Transform Hologram Camera System

Velocity synchronized Fourier transform hologram camera syste

Melt-growth dynamics in CdTe crystals

We use a new, quantum-mechanics-based bond-order potential (BOP) to reveal melt-growth dynamics and fine-scale defect formation mechanisms in CdTe crystals. Previous molecular dynamics simulations of semiconductors have shown qualitatively incorrect behavior due to the lack of an interatomic potential capable of predicting both crystalline growth and property trends of many transitional structures encountered during the melt $\rightarrow$ crystal transformation. Here we demonstrate successful molecular dynamics simulations of melt-growth in CdTe using a BOP that significantly improves over other potentials on property trends of different phases. Our simulations result in a detailed understanding of defect formation during the melt-growth process. Equally important, we show that the new BOP enables defect formation mechanisms to be studied at a scale level comparable to empirical molecular dynamics simulation methods with a fidelity level approaching quantum-mechanical method