E. Gottschalk

The narrow dip observed at 1.9 GeV/c2 by the Fermilab experiment E687 in diffractive photoproduction of 3π+3π− is examined. The E687 data are refitted, a mechanism is proposed to explain why this resonance appears as a dip, and possible interpretations are discussed.

Using data from the FOCUS experiment we analyze the D+π− and D0π+ invariant mass distributions. We measure the D2∗0 mass MD2∗0=(2464.5±1.1±1.9)MeV/c2 and width ΓD2∗0=(38.7±5.3±2.9)MeV/c2, and the D2∗+ mass MD2∗+=(2467.6±1.5±0.76)MeV/c2 and width ΓD2∗+=(34.1±6.5±4.2)MeV/c2. We find evidence for broad structures over background in both the neutral and charged final state. If each is interpreted as evidence for a single L=1, jq=1/2 excited charm meson resonance, the masses and widths are M1/20=(2407±21±35)MeV/c2, Γ1/20=(240±55±59)MeV/c2, and M1/2+=(2403±14±35)MeV/c2, Γ1/2+=(283±24±34)MeV/c2, respectively.

We have performed a search for CPT violation in neutral charm meson oscillations. While flavor mixing in the charm sector is predicted to be small by the Standard Model, it is still possible to investigate CPT violation through a study of the proper time dependence of a CPT asymmetry in right-sign decay rates for D0→K−π+ and D0→K+π−. This asymmetry is related to the CPT violating complex parameter ξ and the mixing parameters x and y: ACPT∝(Reξ)y−(Imξ)x. Our 95% confidence level limit is −0.0068<(Reξ)y−(Imξ)x<0.0234. Within the framework of the Standard Model Extension incorporating general CPT violation, we also find 95% confidence level limits for the expressions involving coefficients of Lorentz violation of (−2.8<N(x,y,δ)(Δa0+0.6ΔaZ)<4.8)×10−16 GeV, (−7.0<N(x,y,δ)ΔaX<3.8)×10−16 GeV, and (−7.0<N(x,y,δ)ΔaY<3.8)×10−16 GeV, where N(x,y,δ) is the factor which incorporates mixing parameters x, y and the doubly Cabibbo-suppressed to Cabibbo-favored relative strong phase δ.

FOCUS results from Dalitz plot analyses of D+s and D+ to π+π−π+ are presented. The K-matrix formalism is applied to charm decays for the first time, which allows us to fully exploit the already existing knowledge coming from light-meson spectroscopy experiments. In particular all the measured dynamics of the S-wave ππ scattering, characterized by broad/overlapping resonances and large non-resonant background, can be properly included. This Letter studies the extent to which the K-matrix approach is able to reproduce the observed Dalitz plot and thus help us to understand the underlying dynamics. The results are discussed along with their possible implications for the controversial σ meson.

A narrow dip structure has been observed at 1.9 GeV/c2 in a study of diffractive photoproduction of the 3π+3π− final state performed by the Fermilab experiment E687.

Modernizing the Fermilab accelerator control system is essential to future operations of the laboratory's accelerator complex. The existing control system has evolved over four decades and uses hardware that is no longer available and software that uses obsolete frameworks. The Accelerator Controls Operations Research Network (ACORN) Project will modernize the control system and replace end-of-life power supplies to enable future accelerator complex operations with megawatt particle beams. An overview of the ACORN Project and a summary of recent research and development activities will be presented.

Total cross sections for Σ− and π− on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c . These measurements were performed with a transmission technique in the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron–nucleus cross sections and on results for σtot(Σ−N) and σtot(π−N) , which were deduced from nuclear cross sections.

Using data from the FOCUS (E831) experiment, we have searched for T violation in charm meson decays using the four-body decay channels $D^0 \to K^-K^+\pi^-\pi^+$, $D^+ \to K^0_SK^+\pi^-\pi^+$, and $D^+_s \to K^0_SK^+\pi^-\pi^+$. The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. We find the asymmetry values to be $A_Tviol (D^0) = 0.010 \pm 0.057(stat.) \pm 0.037(syst.)$, $A_Tviol (D^+) = 0.023 \pm 0.062(stat.) \pm 0.022(syst.)$, and $A_Tviol (D^+_s) = -0.036 \pm 0.067(stat.) \pm 0.023(syst.)$. Each measurement is consistent with no T violation. New measurements of the CP asymmetries for some of these decay modes are also presented.

We describe a silicon microstrip detector interleaved with segments of a beryllium oxide target which was used in the FOCUS photoproduction experiment at Fermilab. The detector was designed to improve the vertex resolution and to enhance the reconstruction efficiency of short-lived charm particles.

We present an analysis of the decay D0→K+π− based on FOCUS data. From a sample of 234 signal events, we find a branching ratio of Γ(D0→K+π−)Γ(D0→K−π+)=(0.429−0.061+0.063±0.027)% under the assumptions of no mixing and no CP violation. Allowing for CP violation, we find a branching ratio of (0.429±0.063±0.028)% and a CP asymmetry of 0.18±0.14±0.04. The branching ratio for the case of mixing with no CP violation is (0.381−0.163+0.167±0.092)%. We also present limits on charm mixing.

BTeV is a collider experiment that has been approved to run in the Tevatron at Fermilab. The experiment will conduct precision studies of CP violation using a forward-geometry detector. The detector will be optimized for high-rate detection of beauty and charm particles produced in collisions between protons and anti-protons. BTeV will trigger on beauty and charm events by taking advantage of the main difference between these heavy quark events and more typical hadronic events—the presence of detached beauty and charm decay vertices. The first stage of the BTeV trigger will receive data from a pixel vertex detector at a rate of 100gbs−1, reconstruct tracks and vertices for every beam crossing, reject 99% of beam crossings that do not produce beauty or charm particles, and trigger on beauty events with high efficiency. An overview of the trigger design and its influence on the design of the pixel vertex detector is presented.

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D+-->K(S)pi+ and D+-->K(S)K+. We have measured the following asymmetry parameters relative to D+-->K-pi+pi+: A(CP)(K(S)pi+) = (-1.6+/-1.5+/-0.9)%, A(CP)(K(S)K+) = (+6.9+/-6.0+/-1.5)%, and A(CP)(K(S)K+) = (+7.1+/-6.1+/-1.2)% relative to D+-->K(S)pi+. We have also measured the relative branching ratios and found Gamma(D+-->K(0)pi+)/Gamma(D+-->K-pi+pi+) = (30.60+/-0.46+/-0.32)%, Gamma(D+-->K(0)K+)/Gamma(D+-->K-pi+pi+) = (6.04+/-0.35+/-0.30)%, and Gamma(D+-->K(0)K+)/Gamma(D+-->K(0)pi+) = (19.96+/-1.19+/-0.96)%.

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter αΛc in Λc+→Λπ+ decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter A≡αΛc+αΛ¯cαΛc−αΛ¯c. We obtain αΛc=−0.78±0.16±0.19 and A=−0.07±0.19±0.24 where errors are statistical and systematic.

We describe the various techniques developed in the Fermilab Wideband Experiments, E687 and FOCUS, to reconstruct long-lived states. The techniques all involve modifications to standard tracking techniques and are useful to report for future experiments.

We present a search for a pentaquark decaying strongly to pKS0 in γN collisions at a center-of-mass energy up to 25 GeV. Finding no evidence for such a state in the mass range of 1470MeV/c2 to 2200MeV/c2, we set limits on the yield and on the cross section times branching ratio relative to Σ∗(1385)± and K∗(892)+.

Using data collected by the fixed target Fermilab experiment FOCUS, we present several first measurements for the semileptonic decay D0→K¯0π−μ+ν. Using a model that includes a K¯0π− s-wave component, we measure the form factor ratios to be rv=1.71±0.68±0.34 and r2=0.91±0.37±0.10 and the s-wave amplitude to be A=0.35±0.22±0.05GeV−1. Finally, we measure the vector semileptonic branching ratio Γ(D0→K*(892)−μ+ν)Γ(D0→K¯0π−π+)=0.337±0.034±0.013.

A precise determination of the charm-strange baryon Cascade(c)+ lifetime is presented. The data were accumulated by the Fermilab high-energy photoproduction experiment FOCUS. The measurement is made with 300 Cascade(c)+ --> Cascade- pi+ pi+ decays, 130 Cascade(c)+ --> Sigma+ K- pi+ decays, 45 Cascade(c)+ --> p K- pi+ decays and 58 Cascade(c)+ --> Lambda K- pi+ pi+ decays. The Cascade(c)+ lifetime is measured to be 0.439+/-0.022+/-0.009 ps.

Using the FOCUS spectrometer with photon beam energies between 20 and 160 \gev, we confirm the existence of a diffractively photoproduced enhancement in $K^+K^-$ at 1750 \mevcc with nearly 100 times the statistics of previous experiments. Assuming this enhancement to be a single resonance with a Breit-Wigner mass shape, we determine its mass to be $1753.5\pm 1.5\pm 2.3$ \mevcc and its width to be $122.2\pm 6.2\pm 8.0$ \mevcc. We find no corresponding enhancement at 1750 \mevcc in $K^*K$, and again neglecting any possible interference effects we place limits on the ratio $\Gamma (X(1750) \to K^*K)/\Gamma (X(1750) \to K^+K^-)$. Our results are consistent with previous photoproduction experiments, but, because of the much greater statistics, challenge the common interpretation of this enhancement as the $\phi (1680)$ seen in $e^+e^-$ annihilation experiments.

A high statistics measurement of the Lambda(+)(c) lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat) +/- 2.5 (syst) fs from 8034 +/- 122 Lambda(+)(c)-->pK(-)pi(+) decays represents a significant improvement over the present world average.

Received 13 February 2002DOI:https://doi.org/10.1103/PhysRevLett.88.159903©2002 American Physical Society

Using data collected by the high energy photoproduction experiment FOCUS at Fermilab we study the doubly and singly Cabibbo suppressed decays D+ and Ds+ --> K+ pi+ pi-. Branching ratios and Dalitz plot analyses are performed.

The CMS Experiment at the LHC is establishing a global network of inter-connected "CMS Centres" for controls, operations and monitoring. These support: (1) CMS data quality monitoring, detector calibrations, and analysis; and (2) computing operations for the processing, storage and distribution of CMS data. We describe the infrastructure, computing, software, and communications systems required to create an effective and affordable CMS Centre. We present our highly successful operations experiences with the major CMS Centres at CERN, Fermilab, and DESY during the LHC first beam data-taking and cosmic ray commissioning work. The status of the various centres already operating or under construction in Asia, Europe, Russia, South America, and the USA is also described. We emphasise the collaborative communications aspects. For example, virtual co-location of experts in CMS Centres Worldwide is achieved using high-quality permanently-running "telepresence" video links. Generic Web-based tools have been developed and deployed for monitoring, control, display management and outreach.

Using data from the FOCUS experiment (FNAL-E831), we report on the decay of $D^0$ mesons into final states containing more than one $K^0_S$. We present evidence for two Cabibbo favored decay modes, $D^0\to K^0_SK^0_S K^- \pi^+$ and $D^0\to K^0_SK^0_S K^+ \pi^-$, and measure their combined branching fraction relative to $D^0\to \bar{K} ^0\pi^+\pi^-$ to be $\frac{\Gamma(D^0\to K^0_SK^0_SK^{\pm}\pi^{\mp})}{\Gamma(D^0\to \bar{K} ^0\pi^+\pi^-)}$ = 0.0106 $\pm$ 0.0019 $\pm$ 0.0010. Further, we report new measurements of $\frac{\Gamma(D^0\to K^0_SK^0_SK^0_S)}{\Gamma(D^0\to \bar{K} ^0\pi^+\pi^-)}$ = 0.0179 $\pm$ 0.0027 $\pm$ 0.0026, $\frac{\Gamma(D^0\to K^0\bar{K} ^0)}{\Gamma(D^0\to \bar{K} ^0\pi^+\pi^-)}$ = 0.0144 $\pm$ 0.0032 $\pm$ 0.0016, and $\frac{\Gamma(D^0\to K^0_SK^0_S\pi^+\pi^-)}{\Gamma(D^0\to \bar{K} ^0\pi^+\pi^-)}$ = 0.0208 $\pm$ 0.0035 $\pm$ 0.0021 where the first error is statistical and the second is systematic.

We report the first observation of diffractively produced open charm in 800-GeV/c pp collisions of the type pp-->pD*X. We measure cross sections of sigma(diff)(D*+) = (0.185+/-0.044+/-0.054) (mu)b and sigma(diff)(D(*-)) = (0.174+/-0.034+/-0.029) (mu)b. Our measurements are based on 4.3x10(9) events recorded by FNAL E690 in the fixed-target run of 1991. We compare our results with previous fixed-target charm experiments.

We have studied the Cabibbo suppressed decay Λc+ → Σ+K*0(892) and the Cabibbo favored decays Λc+ → Σ+K+K−, Λc+ → Σ+ϕ and Λc+ → Ξ*0(Σ+K−)K+ and measured their branching ratios relative to Λc+ → Σ+π+π− to be (7.8 ± 1.8 ± 1.3)%, (7.1 ± 1.1 ± 1.1)%, (8.7 ± 1.6 ± 0.6)% and (2.2 ± 0.6 ± 0.6)%, respectively. The first error is statistical and the second is systematic. We also report two 90% confidence level limits Γ(Λc+ → Σ−K+π+)/Γ(Λc+ → Σ+K*0(892)) < 35% and Γ(Λc+ → Σ+K+K−)NR/Γ(Λc+ → Σ+π+π−) < 2.8%.

The results of the BTeV silicon pixel detector beam test carried out at Fermilab in 1999–2000 are reported. The pixel detector spatial resolution has been studied as a function of track inclination, sensor bias, and readout threshold.

The silicon pixel vertex detector is a key element of the BTeV spectrometer. Sensors bump-bonded to prototype front-end devices were tested in a high energy pion beam at Fermilab. The spatial resolution and occupancies as a function of the pion incident angle were measured for various sensor-readout combinations. The data are compared with predictions from our Monte Carlo simulation and very good agreement is found.

We have studied hadronic four-body decays of D(+) and D(+)(s) mesons with a K(S) in the final state using data recorded during the 1996-1997 fixed-target run of the Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of gamma(D(+)-->K(S)K-pi(+)pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios gamma(D(+)-->K(S)K+pi(+)pi(-))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0562+/-0.0039+/-0.0040, gamma(D(+)-->K(S)K+K-pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0077+/-0.0015+/-0.0009, and gamma(D(+)(s)-->K(S)K+pi(+)pi(-))/gamma(D(+)(s)-->K(S)K-pi(+)pi(+)) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.

This document describes the physics potential of a new fixed-target program based on a ~1 TeV proton source. Two proton sources are potentially available in the future: the existing Tevatron at Fermilab, which can provide 800 GeV protons for fixed-target physics, and a possible upgrade to the SPS at CERN, called SPS+, which would produce 1 TeV protons on target. In this paper we use an example Tevatron fixed-target program to illustrate the high discovery potential possible in the charm and neutrino sectors. We highlight examples which are either unique to the program or difficult to accomplish at other venues.

We study the decay of D+ and D+s mesons into charged five-body final states, and report the discovery of the decay mode D+→K+K−π+π+π−, as well as measurements of the decay modes D+→K−π+π+π+π−, Ds+→K+K−π+π+π−, Ds+→φπ+π+π− and D+/Ds+→π+π+π+π−π−. An analysis of the resonant substructure for D+→K−π+π+π+π− and Ds+→K+K−π+π+π− is included, with an indication that both decays proceed primarily through an a1 vector resonance.

A hardware hash sorter for the Fermilab BTeV Level I trigger system will be presented. The hash sorter examines track-segment data before the data are sent to a system comprised of 2500 Level 1 processors, and rearranges the data into bins based on the slope of track segments. We have found that by using the rearranged data, processing time is significantly reduced allowing the total number of processors required for the Level 1 trigger system to be reduced. The hash sorter can be implemented in an FPGA that is already included as part of the design of the trigger system. Hash sorting has potential applications in a broad area in trigger and DAQ systems. It is a simple O(n) process and is suitable for FPGA implementation. Several implementation strategies will also be discussed in this document.

The scale and performance parameters of the ILC require new thinking in regards to control system design. This design work has begun quite early in comparison to most accelerator projects, with the goal of uniquely high overall accelerator availability. Among the design challenges are high control system availability, precision timing and rf phase reference distribution, standardizing of interfaces, operability, and maintainability. We present the current state of the design and take a prospective look at ongoing research and development projects.

The plans, typical of Acorn homes, are compact, carefully thought out, with attention to privacy, good circulation, visually interesting spaces and good exterior elevations.

We describe a track segment recognition scheme called the Tiny Triplet Finder (TTF) that involves the grouping of three hits satisfying a constraint, for example, forming a straight line. The TTF performs this O(n{sup 3}) function in O(n)time. The logic element usage in FPGA implementations of typical track segment recognition functions are O(N{sup 2}), where N is the number of bins in the coordinate considered, while that for the TTF is O( log( )), which is significantly smaller for large N. The TTF is also suitable for software implementation and many other pattern recognition problems.

Using data collected by the FOCUS experiment at Fermilab, we report the discovery of the decay modes D^0 --> K- pi+ pi+ pi+ pi- pi- and D^0 --> pi+ pi+ pi+ pi- pi- pi-. With a sample of 48 +/- 10 reconstructed D^0 --> K- pi+ pi+ pi+ pi- pi- decays and 149 +/- 17 reconstructed D^0 --> pi+ pi+ pi+ pi- pi- pi- decays, we measure the following relative branching ratios: ${\Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^+ \pi^- \pi^-) / \Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^-)} = (2.70 \pm 0.58 \pm 0.38) \times 10^{-3}$ ${\Gamma (D^0 \to \pi^+ \pi^+ \pi^+ \pi^- \pi^- \pi^-) / \Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^-)} = (5.23 \pm 0.59 \pm 1.35) \times 10^{-3}$ ${\Gamma (D^0 \to \pi^+ \pi^+ \pi^+ \pi^- \pi^- \pi^-) / \Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^+ \pi^- \pi^-)} = 1.93 \pm 0.47 \pm 0.48$ The first errors are statistical and the second are systematic. The branching fraction of the Cabibbo suppressed six-body decay mode is measured to be a factor of two higher than the branching fraction of the Cabibbo favored six-body decay mode.

The CMS experiment is about to embark on its first physics run at the LHC. To maximize the effectiveness of physicists and technical experts at CERN and worldwide and to facilitate their communications, CMS has established several dedicated and inter-connected operations and monitoring centres. These include a traditional 'Control Room' at the CMS site in France, a 'CMS Centre' for up to fifty people on the CERN main site in Switzerland, and remote operations centres, such as the 'LHC@FNAL' centre at Fermilab. We describe how this system of centres coherently supports the following activities: (1) CMS data quality monitoring, prompt sub-detector calibrations, and time-critical data analysis of express-line and calibration streams; and (2) operation of the CMS computing systems for processing, storage and distribution of real CMS data and simulated data, both at CERN and at offsite centres. We describe the physical infrastructure that has been established, the computing and software systems, the operations model, and the communications systems that are necessary to make such a distributed system coherent and effective.

The standard least-squares curved track fitting process is tailored for FPGA implementation so that only integer multiplications and additions are needed. To further eliminate multiplication, coefficients in the fitting matrices are carefully chosen so that only shift and accumulation operations are used in the process. Comparison in an example application shows that the fitting errors of the multiplierless implementation are less than 4% bigger than the fitting errors of the exact least-squares algorithm. The implementation is suitable for low-cost, low-power applications in high energy physics detector trigger systems.

A study of hyperon production in fully reconstructed proton-proton interactions at 28 GeV/c (\ensuremath{\surd}s=7.3 GeV) is presented. Features of the data are presented with the aid of a phenomenological model, the LPM, that was developed to study \ensuremath{\Lambda} production reactions. We note the similarities between \ensuremath{\Lambda} reactions and other families of reactions, and show that this surprisingly simple model can be easily adapted to ${\mathrm{\ensuremath{\Xi}}}^{\mathrm{\ensuremath{-}}}$ production reactions. The only significant difference between the \ensuremath{\Lambda} and ${\mathrm{\ensuremath{\Xi}}}^{\mathrm{\ensuremath{-}}}$ data is the observation that \ensuremath{\Lambda} hyperons are produced as leading particles, whereas ${\mathrm{\ensuremath{\Xi}}}^{\mathrm{\ensuremath{-}}}$ hyperons are not. Production cross sections for eight high-multiplicity hyperon reactions are presented. \textcopyright{} 1996 The American Physical Society.

Standard least-squares curved track fitting process is tailored for FPGA implementation. The coefficients in the fitting matrices are carefully chosen so that only shift and accumulation operations are used in the process. The divisions and full multiplications are eliminated. Comparison in an application example shows that the fitting errors of the low resource usage implementation are less than 4% bigger than the fitting errors of the exact least-squares algorithm. The implementation is suitable for low-cost, low-power applications such as high energy physics detector trigger systems.

Successful operation of the LHC and its experiments is crucial to the future of the worldwide high-energy physics program. Remote operations and monitoring centres have been established for the CMS experiment in several locations around the world. The development of remote centres began with the LHC{at}FNAL ROC and has evolved into a unified approach with distributed centres that are collectively referred to as 'CMS Centres Worldwide'. An overview of the development of remote centres for CMS will be presented, along with a synopsis of collaborative tools that are used in these centres today and trends in the development of remote operations capabilities for high-energy physics.

Commissioning the Large Hadron Collider (LHC) and its experiments will be a vital part of the worldwide high energy physics program beginning in 2007. A remote operations center has been built at Fermilab to contribute to commissioning and operations of the LHC and the compact muon solenoid (CMS) experiment, and to develop new capabilities for real-time data analysis and monitoring for LHC, CMS, and grid computing. Remote operations will also be essential to a future International Linear Collider with its multiple, internationally distributed control rooms. In this paper we present an overview of Fermilab's LHC@FNAL remote operations center for LHC and CMS, describe what led up to the development of the center, and describe noteworthy features of the center.

Since the last ICALEPCS, a small multi-region team has developed a reference design model for a control system for the International Linear Collider as part of the ILC Global Design Effort. The scale and performance parameters of the ILC accelerator require new thinking in regards to control system design. Technical challenges include the large number of accelerator systems to be controlled, the large scale of the accelerator facility, the high degree of automation needed during accelerator operations, and control system equipment requiring 'Five Nines' availability. The R&D path for high availability touches the control system hardware, software, and overall architecture, and extends beyond traditional interfaces into the technical systems. Software considerations for HA include fault detection through exhaustive out-of-band monitoring and automatic state migration to redundant systems, while the telecom industry's emerging ATCA standard - conceived, specified, and designed for High Availability - is being evaluated for suitability for ILC front-end electronics.

We report the main results of the BTeV silicon pixel detector beam test carried out at Fermilab during the fixed target run 1999-2000. The tests were performed using a 227 GeV/c pion beam incident on a 6 plane silicon microstrip telescope. Several single-chip silicon pixel planes were placed in the middle of the apparatus. The pixel detector spatial resolution has been studied as a function of track inclination and the number of ADC bits. The effect of an applied external magnetic field was also studied.

We describe a track segment recognition scheme called the tiny triplet finder (TTF) that involves the grouping of three hits satisfying a constraint such as the forming of a straight line. The TTF performs this O(n/sup 3/) function in O(n) time, where n is number of hits in each detector plane. The word "tiny" reflects the fact that the FPGA resource usage is small. The number of logic elements needed for the TTF is O(Nlog(N)), where N is the number of bins in the coordinate considered, which for large N, is significantly smaller than O(N/sup 2/) that many typical implementations of similar functions need to use. The TTF is also suitable for software implementations as well as many other pattern recognition problems.

Contemporary event building approaches use data switches, either homemade or commercial off-the-shelf ones, to merge data from different channels and distribute them among processor nodes. However, in many trigger and DAQ systems, the merging and distributing functions can often be performed in pre-processing stages. By carefully integrating these functions into the upstream pre-processing stages, the events can be built without dedicated switches. In addition to the cost reducing, extra benefits are gain when the event is built early upstream. In this document, an example of the integrated upstream parasitic event building architecture that has been studied for the BTeV level 1 pixel trigger system is described. Several design considerations that experimentalists of other projects might be interested in are also discussed.

The present work describes the architecture and data flow, analysis of a highly parallel processor for the Level 1 Pixel Trigger for the BTeV experiment at Fermilab. First the Level 1 Trigger system, is described. Then the major components are analyzed by resorting to mathematical modeling. Also, behavioral simulations are used to confirm the models. Results from modeling and simulations are fed back into the system in order to improve the architecture, eliminate bottlenecks, allocate sufficient buffering between processes and obtain other important design parameters. An interesting feature of the current analysis is that the models can be extended to a large class of architectures and parallel systems.

The silicon pixel vertex detector is one of the key elements of the BTeV spectrometer. Detector prototypes were tested in a beam at Fermilab. We report here on the measured spatial resolution as a function of the incident angles for different sensor-readout electronics combinations. We compare the results with predictions from our Monte Carlo simulation.

Fermilab is developing a prototype science data processing and data quality monitoring system for dark energy science. The purpose of the prototype is to demonstrate distributed data processing capabilities for astrophysics applications, and to evaluate candidate technologies for trade-off studies. We present the architecture and technical aspects of the prototype, including an open source scientific execution and application development framework, distributed data processing, and publish/subscribe message passing for quality control.

Background In 2010 the Home Office set up an initiative to engage Community Safety Partnerships (CSPs) across England and Wales in exploring how local partnership working could be used to more effectively tackle organised crime. This report presents the main findings from a process evaluation undertaken of the 12 pilot sites included in this initiative.

Successful operation of the LHC and its experiments is crucial to the future of the worldwide high-energy physics program. Remote operations and monitoring centres have been established for the CMS experiment in several locations around the world. The development of remote centres began with the LHC@FNAL ROC and has evolved into a unified approach with distributed centres that are collectively referred to as "CMS Centres Worldwide." An overview of the development of remote centres for CMS will be presented, along with a synopsis of collaborative tools that are used in these centres today and trends in the development of remote operations capabilities for high-energy physics.

This document describes the physics potential of a new fixed-target program based on a {approx} TeV proton source. Two proton sources are potentially available in the future: the existing Tevatron at Fermilab, which can provide 800 GeV protons for fixed-target physics, and a possible upgrade to the SPS at CERN, called SPS+, which would produce 1 TeV protons on target. In this paper we use an example Tevatron fixed-target program to illustrate the high discovery potential possible in the charm and neutrino sectors. We highlight examples which are either unique to the program or difficult to accomplish at other venues.

We determined Λ0 polarization as function of XF, PT, MX, and EΛ, with respect to the normal of the following two different production planes: The first one defined by the momentum of the 800 GeV/c proton beam and the moment of Λ0; the second one, by the momentum of the transferred object and the momentum of Λ0, from the sample created in the FNAL E690 experiment. We present results, compare and discuss them.

detector and data acquisition flight hardware, maintaining the operating configuration of the LAT and its calibration, and applying event reconstruction processing to down-linked LAT data to recover information about detected gamma-ray photons. The SLAC computer farm will be used to process LAT event data and generate science products, to be made available to the LAT collaboration through the ISOC and to the broader scientific community through the GLAST Science Support Center at NASA/GSFC. ISOC science operations will optimize the performance of the LAT and oversee automated science processing of LAT data to detect and monitor transient gamma-ray sources.

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 D̄ 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.

The polarization of 1973 {Lambda}{sup 0}'s from the specific reaction pp {yields} p{Lambda}{sup 0}K{sup +}({pi}{sup +}{pi}{sup -}){sup 5} created by 27.5 Gev incident protons on a liquid hydrogen target, as a function of {chi}{sub F}, P{sub T}, and M{sub {Lambda}{sup 0}K{sup +}}, is, within statistics, consistent with the polarization of {Lambda}{sup 0}'s from pp {yields} P{sub fast} {Lambda}{sup 0}K{sup +} at 800 GeV.

This paper studies how processor failures affect the dataflow of the Level 1 Trigger in the BTeV experiment proposed to run at Fermilab's Tevatron. The failure analysis is crucial for a system with over 2500 processing nodes and a number of storage units and communication links of the same order of magnitude. This paper is based on models of the L1 Trigger architecture and shows the dynamics of the architecture's dataflow. The dataflow analysis provides insight into how system variables are affected by single component failures and provides key information to the implementation of error recovery strategies. The analysis includes both short-term failures from which the system can recover quickly and long-term failures which imply a more drastic error-recovery strategy. The modeling results are supported by behavioral simulations of the L1 Trigger processing BTeV's GEANT Monte Carlo data.

We describe the applications of a track segment recognition scheme called the Tiny Triplet Finder (TTF) that involves the grouping of three hits satisfying a constraint forming of a track segment. The TTF was originally developed solving straight track segment finding problem, however, it is also suitable in many curved track segment finding problems. The examples discussed in this document are among popular detector layouts in high-energy/nuclear physics experiments. Although it is not practical to find a universal recipe for arbitrary detector layouts, the method of the TTF application is illustrated via the discussion of the examples. Generally speaking, whenever the data item to be found in a pattern recognition problem contains two free parameters, and if the constraint connecting the measurements and the two free parameters has an approximate shift invariant property, the tiny triplet finder can be used.

A facility, LHC@FNAL, is being constructed at Fermi- lab to help people contribute remotely to the Large Had- ron Collider (LHC) effort at CERN. As a facility, LHC@FNAL has three primary functions: 1. To provide access to information in a manner that is similar to what is available in control rooms at CERN, and to enable members of the LHC community to par- ticipate remotely in LHC and CMS (1) activities. 2. To serve as a communications conduit between CERN and members of the LHC community located in North America. 3. To allow visitors to Fermilab to see firsthand how re- search is progressing at the LHC. Visitors will be able to see current LHC activities, and to see how future international projects in particle physics can benefit from active participation from remote locations.

Fixed-target experiments continue to provide insights into the physics of particle production in strong interactions. The experiments are performed with different types of beam particles of varying energies, and many different target materials. Studies of beauty and charm production are of particular interest, since experimental results can be compared to perturbative QCD calculations. It is in this context that recent results from fixed-target experiments on beauty and charm production will be reviewed.

Over 7000 events containing a fully reconstructed DD pair have been extracted from data recorded by the FOCUS photoproduction experiment at Fermilab. Preliminary results from a study of correlations between D and D mesons are presented. Correlations are used to study perturbative QCD predictions and investigate non-perturbative effects. We also present a preliminary result on the production of Ψ(3770).

The current paper studies how processor failures affect the dataflow of the Level I Trigger in the BTeV experiment proposed to run at Fermilab's Tevatron. The failure analysis is crucial for a system with over 2500 processing nodes and a number of storage units and communication links of the same order of magnitude. The failure analysis is based on models of the L1 Trigger architecture and shows the dynamics of the architecture's dataflow. The failure analysis provides insight into how system variables are affected by single component failures and provides key information to the implementation Of error recovery strategies. The analysis includes both short term failures from which the system can recover quickly and long term failures which imply a more drastic error recovery strategy. The modeling results are supported by behavioral simulations of the L1 Trigger processing BTeV's Geant Monte Carlo data.

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.

Over 7000 events containing a fully reconstructed D{bar D} pair have been extracted from data recorded by the FOCUS photoproduction experiment at Fermilab. Preliminary results from a study of correlations between D and {bar D} mesons are presented. Correlations are used to study perturbative QCD predictions and investigate non-perturbative effects. We also present a preliminary result on the production of {psi}(3770).

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D → K S π + and D + → K S K + . We have measured the following asymmetry parameters relative to D + → K - π + π + : A C P (K S π + ) = (-1.6 ′ 1.5 ′ 0.9)%, A C P (K S K + ) = (+6.9 ′ 6.0 ′ 1.5)%, and A C P (K S K + ) = (+7.1 ′ 6.1 ′ 1.2)% relative to D + → K S π + . We have also measured the relative branching ratios and found Γ(D + + K 0 π + )/Γ(D + → K π + π + ) = (30.60 ′ 0.46 ′ 0.32)%, Γ(D + → K 0 K + )/Γ(D + → K - π + π + ) = (6.04 ′ 0.35 ′ 0.30)%, and Γ(D + → K 0 K + )/Γ(D + → K 0 π + ) = (19.96 ′ 1.19 ′ 0.96)%.

Over the years fixed-target experiments have performed numerous studies of particle production in strong interactions. The experiments have been performed with different types of beam particles of varying energies, and many different target materials. Since the physics of particle production is still not understood, ongoing research of phenomena that we observe as beauty, charm and strange-particle production is crucial if we are to gain an understanding of these fundamental processes. It is in this context that recent results from fixed-target experiments on beauty, charm, and hyperon production will be reviewed.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation M. C. Berisso, D. C. Christian, J. Felix, A. Gara, E. Gottschalk, G. Gutierrez, E. P. Hartouni, B. C. Knapp, M. N. Kreisler, S. Lee, K. Markianos, G. Moreno, M. A. Reyes, M. Sosa, M. H. L. S. Wang, A. Wehmann, D. Wesson; Recent results from Fermilab E690. AIP Conf. Proc. 29 May 1998; 432 (1): 36–46. https://doi.org/10.1063/1.55997 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Results are presented from a partial wave analysis of a sample of centrally produced mesons in the reaction pp→pslow(KsKs)pfast, with 800 GeV/c protons incident on a liquid hydrogen target. The meson system is found to be predominantly S-wave in the mass range between KsKs threshold and 1.58 GeV/c2. The f0(1500) is clearly observed in this region. Above 1.58 GeV/c2 two solutions are possible, one with mainly S-wave and another with mainly D-wave. This ambiguity prevents a unique determination of the spin of the fJ(1710) meson.

BTeV is a collider experiment at Fermilab designed for precision studies of CP violation and mixing. Unlike most collider experiments, the BTeV detector has a forward geometry that is optimized for the measurement of B and charm decays in a high-rate environment. While the rate of B production gives BTeV an advantage of almost four orders of magnitude over e+e- B factories, the BTeV Level 1 trigger must be able to accept data at a rate of 100 Gigabytes per second, reconstruct tracks and vertices, trigger on B events with high efficiency, and reject minimum bias events by a factor of 100:1. An overview of the Level 1 trigger will be presented.

BTeV is a collider experiment at Fermilab designed for precision studies of CP violation and mixing. Unlike most collider experiments, the BTeV detector has a forward geometry that is optimized for the measurement of B and charm decays in a high-rate environment. While the rate of B production gives BTeV an advantage of almost four orders of magnitude over e+e- B factories, the BTeV Level 1 trigger must be able to accept data at a rate of 100 Gigabytes per second, reconstruct tracks and vertices, trigger on B events with high efficiency, and reject minimum bias events by a factor of 100:1. An overview of the Level 1 trigger will be presented.

This brief talk will present the very preliminary results of an ongoing data analysis of the data from BNL E766. BNL E766 was an experiment to study heavy particle spectroscopy in np(15−24 GeV) and pp interactions (28 GeV). The following discussion pertains to the pp → ppKsoKπ run. (AIP)