The authors report the first KTeV measurement for the search of direct-CP violation by using 23% of the data sample collected in the 1996-97 fixed target run at Fermilab. The result is, Re({epsilon}{prime}/{epsilon}) = (28.0 {+-} 4.1) x 10{sup -4}, nearly 7{delta} above zero obtained by a blind analysis. This firmly establishes the long-sought direct-CP violation effect in the two-pion system ({pi}{sup +}{pi}{sup -} versus {pi}{sup 0}{pi}{sup 0}) of neutral kaon decays.

Recent improvements in z-pinch wire array load design at Sandia National Laboratories have led to a substantial increase in pinch performance as measured by radiated powers of up to 280 TW in 4 ns and 1.8 MJ of total radiated energy. Next generation, higher current machines will allow for larger mass arrays and comparable or higher velocity implosions to be reached, possibly extending these result.dis the current is pushed above 20 MA, conventional machine design based on a 100 ns implosion time results in higher voltages, hence higher cost and power flow risk. Another approach, which shifts the risk to the load configuration, is to increase the implosion time to minimize the voltage. This approach is being investigated in a series of experimental campaigns on the Saturn and Z machines. In this paper, both experimental and two dimensional computational modeling of the fist long implosion Z experiments will be presented. The experimental data shows broader pulses, lower powers, and larger pinch diameters compared to the corresponding short pulse data. By employing a nested array configuration, the pinch diameter was reduced by 50% with a corresponding increase in power of > 30%. Numerical simulations suggest load velocity is the dominating mechanism …

Isosurface extraction is an important and useful visualization method. Over the past ten years, the field has seen numerous isosurface techniques published leaving the user in a quandary about which one should be used. Some papers have published complexity analysis of the techniques yet empirical evidence comparing different methods is lacking. This case study presents a comparative study of several representative isosurface extraction algorithms. It reports and analyzes empirical measurements of execution times and memory behavior for each algorithm. The results show that asymptotically optimal techniques may not be the best choice when implemented on modern computer architectures.

Electrochemical corrosion tests have been conducted on simulated stainless steel-zirconium (SS-Zr) metal waste form (MWF) samples. The uniform aqueous corrosion behavior of the samples in various test solutions was measured by the polarization resistance technique. The data show that the MWF corrosion rates are very low in groundwaters representative of the proposed Yucca Mountain repository. Galvanic corrosion measurements were also conducted on MWF samples that were coupled to an alloy that has been proposed for the inner lining of the high-level nuclear waste container. The experiments show that the steady-state galvanic corrosion currents are small. Galvanic corrosion will, hence, not be an important mechanism of radionuclide release from the MWF alloys.

The goals of this paper are to (1) ascertain the ability of atmospheric general circulation models to hindcast the summer monsoons of 1987, 1988, and 1993, (2) to determine how well the models represent the dominant modes of subseasonal variability of the 850hPa flow, (3) to determine if the models can represent the strong link between the subseasonal modes of variability and the rainfall, (4) to determine if the models properly project these modes onto interannual timescales, (5) to determine if it is possible to objectively discriminate among the ensemble members to ascertain which members are most reliable. The results presented here are based upon contributions to the seasonal prediction model intercomparison project (SMIP), which was initiated by the CLIVAR Working Group on Seasonal to Interannual Prediction (WGSIP; formally Numerical Experimentation Group-1). For each summer, June--September, ensembles of integrations were performed using observed initial conditions, and observed sea surface temperatures. Here, the results from a 4-member ensemble from the United Kingdom Met Office (UKMO) model are presented for the sake of brevity. The conclusions based on the analysis of this model are consistent with the behavior of the other models.

Improving our knowledge of the morphology, composition and properties of the dentin, enamel, and the dentin-enamel junction (DEJ) is vital for the development of improved restorative materials and clinical placement techniques. Most studies of dental tissues have used light microscopy for characterization. In our investigation, the spectroscopic properties of normal and non-carious transparent human root dentin, and the dentin-enamel junction were investigated using emission imaging microscopy, and micro-spectroscopy. Experimental results reveal new information on the structural and biochemical characteristics of these dental tissues.

Since the first observation in 1964, CP violation remains one of the most elusive aspects of the standard model. The CDF collaboration has reported the first evidence of CP violation in the B system using the world's largest sample of B {yields} J/{psi}K{sub S}{sup 0} decays. The direct measurement of sin(2{beta})=0.79{sub -0.44}{sup +0.41} (combined statistical and systematic error) agrees with the standard model predictions. New data collected from the B-factories and from the upgraded experiments at the Tevatron should allow a more precise measurement of sin 2{beta} in the near future.

We report the first KTeV measurement for the search of direct-CP violation by using 23% of the data sample collected in the 1996-97 fixed target run at Fermilab. The result is, Re({epsilon}{prime}/{epsilon}) = (28.0 {+-} 4.1) x 10{sup -4}, nearly 7{delta} above zero obtained by a blind analysis. This firmly establishes the long-sought ''direct-CP violation'' effect in the two-pion system ({pi}{sup +}{pi}{sup -} versus {pi}{sup 0}{pi}{sup 0}) of neutral kaon decays. Other new measurements of {Delta}m, {tau}{sub s}, {Delta}{phi} and a limit on the diurnal variation of {phi}{sub +-} for testing CPT invariance from the same data sample are also presented.

The current status of the muon collider is presented, with a brief historical review. The proton source and the pion production and decay channel needed for a first muon collider (FMC) are described. A brief review of ionization cooling theory is followed by the current status of cooling ideas. The acceleration scheme and the collider ring are presented, followed by the backgrounds expected in a muon collider detector and the physics potential of such a detector. The physics potential of a muon storage ring that acts as an intense neutrino source of well-defined flavor is reviewed.

Theoretical predictions for B decay rates are rewritten in terms of the Upsilon meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency is shown both at low and high orders. This method improves the behavior of the perturbation series for inclusive and exclusive decay rates, and the largest theoretical error in the predictions coming from the uncertainty in the quark mass is eliminated. Applications to the determination of CKM matrix elements, moments of inclusive decay distributions, and the {bar B} {yields} X{sub s}{gamma} photon spectrum are discussed.

We present recent results on measurements of the transverse momentum distribution of W and Z bosons, the angular distribution of electrons from W decays, and on color coherence effects in W+jets events from p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron Collider. The data are compared to perturbative QCD calculations.

It is presented a comparative performance study of a coarse grained parallel neural network training code, implemented in both OpenMP and MPI, standards for shared memory and message passing parallel programming environments, respectively. In addition, these versions of the parallel training code are compared to an implementation utilizing SHMEM the native SGI/CRAY environment for shared memory programming. The multiprocessor platform used is a SGI/Cray Origin 2000 with up to 32 processors. It is shown that in this study, the native CRAY environment outperforms MPI for the entire range of processors used, while OpenMP shows better performance than the other two environments when using more than 19 processors. In this study, the efficiency is always greater than 60% regardless of the parallel programming environment used as well as of the number of processors.

A monoenergetic neutron beam simulation study is carried out to determine the optimal neutron energy range for treatment of rheumatoid arthritis using radiation synovectomy. The goal of the treatment is the ablation of diseased synovial membranes in joints, such as knees and fingers. This study focuses on human knee joints. Two figures-of-merit are used to measure the neutron beam quality, the ratio of the synovium absorbed dose to the skin absorbed dose, and the ratio of the synovium absorbed dose to the bone absorbed dose. It was found that (a) thermal neutron beams are optimal for treatment, (b) similar absorbed dose rates and therapeutic ratios are obtained with monodirectional and isotropic neutron beams. Computation of the dose distribution in a human knee requires the simulation of particle transport from the neutron source to the knee phantom through the moderator. A method was developed to predict the dose distribution in a knee phantom from any neutron and photon beam spectra incident on the knee. This method was revealed to be reasonably accurate and enabled one to reduce by a factor of 10 the particle transport simulation time by modeling the moderator only.