The production of a Higgs boson in association with a pair of t{bar t} or b{bar b} quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief description of the most relevant technical aspects of the calculation, we review the results obtained for both the Tevatron and the Large Hadron Collider.

This paper examines current trends in Positron Emission Mammography (PEM) instrumentation and the performance tradeoffs inherent in them. The most common geometry is a pair of parallel planes of detector modules. They subtend a larger solid angle around the breast than conventional PET cameras, and so have both higher efficiency and lower cost. Extensions to this geometry include encircling the breast, measuring the depth of interaction (DOI), and dual-modality imaging (PEM and x-ray mammography, as well as PEM and x-ray guided biopsy). The ultimate utility of PEM may not be decided by instrument performance, but by biological and medical factors, such as the patient to patient variation in radiotracer uptake or the as yet undetermined role of PEM in breast cancer diagnosis and treatment.

Computational studies and experimental measurements of plasma injection into a Malmberg-Penning trap reveal that the number of trapped particles can be an order of magnitude higher than predicted by a simple estimates based on a ballistic trapping model. Enhanced trapping is associated with a rich nonlinear dynamics generated by the space-charge forces of the evolving trapped electron density. A particle-in-cell simulation is used to identify the physical mechanisms that lead to the increase in trapped electrons. The simulations initially show strong two-stream interactions between the electrons emitted from the cathode and those reflected off the end plug of the trap. This is followed by virtual cathode oscillations near the injection region. As electrons are trapped, the initially hollow longitudinal phase-space is filled, and the transverse radial density profile evolves so that the plasma potential matches that of the cathode. Simple theoretical arguments are given that describe the different dynamical regimes. Good agreement is found between simulation and theory.

We present the first large-acceptance measurement of event-wise <p{sub t}> fluctuations in Au-Au collisions at {radical}s{sub NN} = 130 GeV. Significant nonstatistical fluctuations are observed. The measured fractional r.m.s. width excess of the event-wise <p{sub t}> distribution for the 15% most-central events for charged hadrons within |{eta}| < 1 and 0.15 {le} p{sub t} {le} 2 GeV/c is 13.7 {+-} 0.1(stat) {+-}1.3(syst)% relative to a statistical reference. The variation of charge-independent fluctuation excess with centrality is non-monotonic but smooth. Charge-dependent nonstatistical fluctuations are also observed.

Noble gases widely exist in nature, and except for radon, they are stable. Modern techniques can detect noble gases to relatively low concentrations and with great precision. These factors suggest that noble gases can be useful tracers for subsurface characterization. Their applications, however, require an appropriate transport model for data analyses. A new fluid property module, EOSN, was developed for TOUGH2 to simulate transport of noble gases in the subsurface. Currently any of five different noble gases (except radon) as well as CO{sub 2} can be selected, two at a time. For the two selected gas components, the Crovetto et al. (1982) model is used to calculate the Henry's law coefficients; and the Reid et al. (1987) correlation is used to calculate the gas phase diffusivities. Like most other sister modules, TOUGH2/EOSN can simulate nonisothermal multiphase flow and fully coupled transport in fractured porous media. Potential applications of the new module include, but are not limited to: (a) study of different reservoir processes such as recharge, boiling, condensation, and fracture-matrix fluid exchange; (b) characterization of reservoir geometry such as fracture spacing; and (c) analysis of CO{sub 2} sequestration.

Energy Information Systems (EIS), which can monitor and analyze building energy consumption and related data throughout the Internet, have been increasing in use over the last decade. Though EIS developers describe the capabilities, costs, and benefits of EIS, many of these descriptions are idealized and often insufficient for potential users to evaluate cost, benefit and operational usefulness. LBNL has conducted a series of case studies of existing EIS and related technology installations. This study explored the following questions: (1) How is the EIS used in day-to-day operation? (2) What are the costs and benefits of an EIS? (3) Where do the energy savings come from? This paper reviews the process of these technologies from installation through energy management practice. The study is based on interviews with operators and energy managers who use EIS. Analysis of energy data trended by EIS and utility bills was also conducted to measure the benefit. This paper explores common uses and findings to identify energy savings attributable to EIS, and discusses non-energy benefits as well. This paper also addresses technologies related to EIS that have been demonstrated and evaluated by LBNL.

The developmental increase in structural complexity in multicellular life forms depends on local, often non-periodic differences in gene expression. These depend on a network of gene-gene interactions coded within the organismal genome. To better understand how genomic information generates complex expression patterns, I have modeled the pattern forming behavior of small artificial genomes in virtual blastoderm embryos. I varied several basic properties of these genomic signaling networks, such as the number of genes, the distributions of positive (inductive) and negative (repressive) interactions, and the strengths of gene-gene interactions, and analyzed their effects on developmental pattern formation. The results show how even simple genomes can generate complex non-periodic patterns under suitable conditions. They also show how the frequency of complex patterns depended on the numbers and relative arrangements of positive and negative interactions. For example, negative co-regulation of signaling pathway components increased the likelihood of (complex) patterns relative to differential negative regulation of the pathway components. Interestingly, neither quantitative differences either in strengths of signaling interactions nor multiple response thresholds to signal concentration (as in morphogen gradients) were essential for formation of multiple, spatially unique cell types. Thus, with combinatorial code of gene regulation and hierarchical signaling interactions, it is theoretically …

The {eta}{sub b} (1S) is the J{sup PC} = 0{sup {-+}} b{bar b} ground state, and has not yet been experimentally observed. Theorists have recently suggested that it could be observed at the Fermilab Tevatron through its decay to J/{psi}J/{psi}, if not in the 1992-96 (''Run 1'') dataset, then in Run 2. This article describes a search for this particle at CDF in Run 1 using this decay channel. A small cluster is seen, with 7 events where 1.8 events are expected from background. The statistical significance is estimated to be 2.2{sigma}, and an upper limit is set on the product of cross section and branching fractions.

Presently there is significant interest at LBNL in designing and building a facility for ultrafast (i.e. femtosecond time scale) x-ray science based upon a superconducting, recirculating RF linac (see Corlett et al. for more details). In addition to producing synchrotron radiation pulses in the 1-15 keV energy range, we are also considering adding one or more free-electron laser (FEL) beamlines using a harmonic cascade approach to produce coherent XUV soft X-ray emission beginning with a strong input seed at {approx}200 nm wavelength obtained from a ''conventional'' laser. Each cascade is composed of a radiator together with a modulator section, separated by a magnetic chicane. The chicane temporally delays the electron beam pulse in order that a ''virgin'' pulse region (with undegraded energy spread) be brought into synchronism with the radiation pulse, which together then undergo FEL action in the modulator. We present various results obtained with the GINGER simulation code examining final output sensitivity to initial electron beam parameters. We also discuss the effects of spontaneous emission and shot noise upon this particular cascade approach which can limit the final output coherence.

Beam-beam phenomena have until now limited the beam currents and luminosity achievable in the Tevatron. injected proton currents are about ten times larger than the anti-proton currents so beam-beam effects have largely acted on the anti-protons and at all stages of the operational cycle. The effects of the anti-protons on the protons have until now been relatively benign but that may change at higher anti-proton currents. After 36 bunches of protons are injected and placed on the proton helix, anti-protons are injected four bunches at a time. After all bunches are injected, acceleration to top energy takes bout 85 seconds. After reaching flat top, the optics around the interaction regions (IRs) is changed to lower {beta}* from 1.6 m to 0.35 m at B0 and D0. The beams are brought into collision by collapsing the separation bumps around the IPs. During a high energy physics store each bunch experiences two head-on collisions with bunches in the opposing beam and seventy long-range interactions. At all other stages of the operational cycle, each bunch experiences only long-range interactions--seventy two in all. Performance limitations from beam-beam effects until now have been primarily due to these long-range interactions. The anti-proton losses at 150 GeV …

Boron-neutron capture therapy (BNCT) is an experimental radiation treatment modality used for highly malignant tumor treatments. Prior to irradiation with low energetic neutrons, a 10B compound is located selectively in the tumor cells. The effect of the treatment is based on the high LET radiation released in the {sup 10}B(n,{alpha}){sup 7}Li reaction with thermal neutrons. BNCT has been used experimentally for brain tumor and melanoma treatments. Lately applications of other severe tumor type treatments have been introduced. Results have shown that liver tumors can also be treated by BNCT. At Lawrence Berkeley National Laboratory, various compact neutron generators based on D-D or D-T fusion reactions are being developed. The earlier theoretical studies of the D-D or D-T fusion reaction based neutron generators have shown that the optimal moderator and reflector configuration for brain tumor BNCT can be created. In this work, the applicability of 2.5 MeV neutrons for liver tumor BNCT application was studied. The optimal neutron energy for external liver treatments is not known. Neutron beams of different energies (1eV < E < 100 keV) were simulated and the dose distribution in the liver was calculated with the MCNP simulation code. In order to obtain the optimal neutron energy …

The authors present their observations of the longitudinal bunch dynamics in Tevatron for uncoalesced proton bunches at 150 GeV and coalesced proton bunches at 150 GeV and 980 GeV. They have observed long-term (> 15 minutes) coherent oscillations of uncoalesced protons that preserve already existing oscillations from upstream accelerators. A single-bunch instability in large intensity protons bunches at 980 GeV has also been observed.

No abstract prepared.

In order to achieve an increase in proton intensity, Fermilab Main Injector will use a stacking process called ''slip stacking''. The intensity will be doubled by injecting one train of bunches at a slightly lower energy, another at a slightly higher energy, then bringing them together for the final capture. Beam studies have started for this process and we have already verified that, at least for a low beam intensity, the stacking procedure works as expected. For high intensity operation, development work of the feedback and feedforward systems is under way.

We present measurements of transverse and longitudinal beam phase space evolution during the first two hundred turns of the FNAL Booster cycle. We discuss the experimental technique, which allowed us to obtain turn-by-turn measurements of the beam profile. The experimental results are compared with the prediction of the Synergia 3D space charge simulation code.

Protons and anti-protons circulate on helical orbits in the Tevatron. At injection energy (150 GeV) the lifetimes of both species are significantly lower on the helical orbits compared to lifetimes on the central orbit but for different reasons. There are also significant beam losses in both beams when they are accelerated to top energy (980 GeV) again for different reasons. They report on experimental studies to determine the reasons and on methods of improving the lifetimes and losses for both beams.

A large sample of events containing fully and partially reconstructed pairs of charmed D mesons has been studied by the Fermilab photoproduction experiment FOCUS (FNAL-E831). Correlations between photoproduced D and {bar D} mesons are used to study heavy quark production dynamics. Correlation results are presented for fully and partially reconstructed pairs of charmed D mesons. The results are compared to Monte Carlo predictions based on a recent version of PYTHIA with default settings.

A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.

This report specifically deals with Savannah River Site augmentation of permanent Criticality Accident Alarm Systems by the use of portable instruments in areas not normally occupied by personnel.

This paper presents analyses of coupled hydrological-mechanical (HM) processes during drilling of the FEBEX tunnel, located in fractured granite at Grimsel, Switzerland. Two and three-dimensional transient finite-element simulations were performed to investigate HM-induced fluid-pressure pulses, observed in the vicinity of the FEBEX tunnel during its excavation in 1995. The results show that fluid-pressure responses observed in the rock mass during TBM drilling of the FEBEX tunnel could not be captured using current estimates of regional stress. It was also shown that the measured pressure responses can be captured in both two and three-dimensional simulations if the stress field is rotated such that contraction (compressive strain rate) and corresponding increases in mean stress occur on the side of the drift, where increased fluid pressure spikes were observed.

Private sector commercial office buildings are challenging environments for energy efficiency projects. This challenge is related to the complexity of business environments that involve ownership, operation, and tenant relationships. This research project was developed to examine the environment for building operations and identify causes of inefficient use of energy related to technical and organizational issues. This paper discusses a second-generation Information Monitoring and Diagnostic System (IMDS) installed at a leased office building in Sacramento, California. The underlying principle of this project is that high quality building performance data can help show where energy is being used and how buildings systems actually perform. Such data are an important first step toward improving building energy efficiency. This project has demonstrated that the IMDS is valuable to the building operators at the Sacramento site. The building operators not only accept the technology, but it has become the core of their day-to-day building control concepts. One objective of this project was to evaluate the costs and benefits of the IMDS. The system cost about $0.70 per square foot, which includes the design, hardware, software, and installation, which is about 30% less than the previous IMDS in San Francisco. A number of operational problems have …

The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton transfers in and out of the Recycler Ring take place through two transfer lines connecting the Recycler to the Main Injector. Transfer line layout and operation of beam transfers will be described. Particular attention has been paid to injection mismatch effects, in order to limit emittance growth during transfers. A considerable improvement has been achieved by removing vacuum windows, previously present in both transfer lines.

Phase and amplitude noises in the Tevatron RF system and the intrabeam scattering (IBS) produce longitudinal emittance growth with consecutive particle loss from the RF buckets. That causes a decrease of the luminosity and an increase of the background in particle detectors during the store. The report presents experimental measurements of RF system noise and the effect on the longitudinal emittance growth. There is a satisfactory agreement between measured noise spectral densities and observed emittance growth. For high bunch intensities, IBS plays an important role and has been taken into account. The sources of noises and plans for further system improvements are discussed.

The top quark, discovered in 1994 at the Tevatron, has proven a very interesting particle. Its characteristics allow both to perform stringent tests of electroweak theory, and to search for new physics through a deviation from standard model predictions for several of its peculiar properties. I will review the status of top physics and briefly describe the potential of experiments of the near future.