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Joel Nathan Butler

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DOI: 10.1016/j.biortech.2012.04.073
2012
Cited 131 times
Nannochloropsis production metrics in a scalable outdoor photobioreactor for commercial applications
Commercial production of renewable energy feedstocks from microalgae will require reliable and scalable growth systems. Two and one half years of biomass and lipid productivity data were obtained with an industrial-scale outdoor photobioreactor operated in Fort Collins, Colorado (USA). The annualized volumetric growth rates for Nannochloropsis oculata (CCMP 525) and Nannochloropsis salina (CCMP 1776) were 0.16 g L(-1) d(-1) (peak=0.37 g L(-1) d(-1)) and 0.15 g L(-1) d(-1) (peak=0.37 g L(-1) d(-1)) respectively. The collective average lipid production was 10.7 m3 ha(-1) yr(-1) with a peak value of 36.3 m3 ha(-1) yr(-1). Results from this study are unique based on publication of biomass and corresponding lipid content combined with demonstration of energy savings realized through analysis of gas delivery requirements, water recycling from successive harvests with no effect on productivity, and culture stability through serial batch lineage data and chemotaxonomic analysis of fatty acid contents.
2015
Cited 88 times
Technical Proposal for the Phase-II Upgrade of the CMS Detector
This Technical Proposal presents the upgrades foreseen to prepare the CMS experiment for the High Luminosity LHC. In this second phase of the LHC physics program, the accelerator will provide to CMS an additional integrated luminosity of about 2500 fb-1 over 10 years of operation, starting in 2025. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented p-p luminosity, the CMS collaboration will need to address the aging of the present detector and to improve the ability of the apparatus to isolate and precisely measure the products of the most interesting collisions. This document describes the conceptual designs and the expected performance of the upgrades, along with the plans to develop the appropriate experimental techniques. The infrastructure upgrades and the logistics of the installation in the experimental area are also discussed. Finally, the initial cost estimates of the upgrades are presented.
DOI: 10.1103/physrevlett.128.132003
2022
Cited 31 times
Measurement of the Nucleon <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>F</mml:mi><mml:mn>2</mml:mn><mml:mi>n</mml:mi></mml:msubsup><mml:mo>/</mml:mo><mml:msubsup><mml:mi>F</mml:mi><mml:mn>2</mml:mn><mml:mi>p</mml:mi></mml:msubsup></mml:math> Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment
The ratio of the nucleon F_{2} structure functions, F_{2}^{n}/F_{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range 0.19<x<0.83, represent a significant improvement compared to previous SLAC and Jefferson Lab measurements for the ratio. They are compared to recent theoretical calculations and empirical determinations of the F_{2}^{n}/F_{2}^{p} ratio.
DOI: 10.1016/s0920-5632(02)01948-5
2003
Cited 114 times
New results on c-baryons and a search for cc-baryons in FOCUS
Chiral symmetry and its spontaneous breaking play an important role both in the light hadron and heavy hadron systems. The chiral perturbation theory (χPT) is the low energy effective field theory of the Quantum Chromodynamics. In this work, we shall review the investigations on the chiral corrections to the properties of the heavy mesons and baryons within the framework of χPT. We will also review the scatterings of the light pseudoscalar mesons and heavy hadrons, through which many new resonances such as the Ds0∗(2317) could be understood.Moreover, many new hadron states were observed experimentally in the past decades. A large group of these states is near-threshold resonances, such as the charged charmoniumlike Zc and Zcs states, bottomoniumlike Zb states, hidden-charm pentaquark Pc and Pcs states and the doubly charmed Tcc state, etc. They are very good candidates of the loosely bound molecular states composed of a pair of charmed (bottom) hadrons, which are very similar to the loosely bound deuteron. The modern nuclear force was built upon the chiral effective field theory (χEFT), which is the extension of the χPT to the systems with two matter fields. The long-range and medium-long-range interactions between two nucleons arise from the single- and double-pion exchange respectively, which are well constrained by the chiral symmetry and its spontaneous breaking. The short-distance interactions can be described by the low energy constants. Such a framework works very well for the nucleon–nucleon scattering and nuclei. In this work, we will perform an extensive review of the progress on the heavy hadronic molecular states within the framework of χEFT. We shall emphasize that the same chiral dynamics not only govern the nuclei and forms the deuteron, but also dictates the shallow bound states or resonances composed of two heavy hadrons.
DOI: 10.1103/physrevlett.48.73
1982
Cited 110 times
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mfrac><mml:mrow><mml:mi>J</mml:mi></mml:mrow><mml:mrow><mml:mi>ψ</mml:mi></mml:mrow></mml:mfrac></mml:math>Photoproduction from 60 to 300 GeV/<i>c</i>
Measurements of the energy and $t$ dependence of diffractive $\frac{J}{\ensuremath{\psi}}$ photoproduction are presented. A significant rise in the cross section over the energy range 60-300 GeV is observed. It is found that (30\ifmmode\pm\else\textpm\fi{}4)% of the events are inelastic.
DOI: 10.1016/s0370-2693(03)00103-5
2003
Cited 101 times
Charm system tests of CPT and Lorentz invariance with FOCUS
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.
DOI: 10.1016/s0370-2693(02)01715-x
2002
Cited 74 times
Evidence for new interference phenomena in the decay D+→K−π+μ+ν
Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present evidence for a small, even spin K−π+ amplitude that interferes with the dominant K̄∗0 component in the D+→K−π+μ+ν final state. Although this interference significantly distorts the D+→K−π+μ+ν decay angular distributions, the new amplitude creates only a very small distortion to the observed kaon pion mass distribution when integrated over the other kinematic variables describing the decay. Our data can be described by K̄∗0 interference with either a constant amplitude or broad spin zero resonance.
2001
Cited 64 times
$B$ physics at the Tevatron: Run II and beyond
This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.
2019
Cited 27 times
A MIP Timing Detector for the CMS Phase-2 Upgrade
DOI: 10.1016/0370-2693(93)90216-5
1993
Cited 50 times
Analysis of the decay mode
Fermilab high-energy photoproduction experiment E687 provides a high statistics sample of the decay mode D+ → K∗0μ+ν (charge conjugates are implied). Our analysis yields a branching ratio of Γ (D+ → K∗0μ+ν)Γ (D+ → K−π+π+) = 0.56±0.04±0.06. The ratios of the form factors governing the decay are measured to be Rν = 1.74 ±0.27±0.28 and R2 = 0.78±0.18±0.10, implying a polarization of ΓlΓt = 1.20±0.13 ±0.13 for the electron decay. Finally, we report new limits on the decay modes D+ → K−π+μ+ν (nonresonent) and D+ → K∗0π0μ+ν.
DOI: 10.1103/physrevd.40.1
1989
Cited 48 times
High-energy photoproduction of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>,<mml:math xmlns:mml="…
We report measurements from elastic photoproduction of $\ensuremath{\omega}'\mathrm{s}$ on hydrogen for photon energies between 60 and 225 GeV, elastic $\ensuremath{\varphi}$ photoproduction on hydrogen between 35 and 165 GeV and on deuterium between 45 and 85 GeV, elastic photoproduction on deuterium of an enhancement at 1.72 GeV/${\mathit{c}}^{2}$ decaying into ${K}^{+}{K}^{\ensuremath{-}}$, and elastic and inelastic photoproduction on deuterium of $p\overline{p}$ pairs.
DOI: 10.1016/j.physletb.2009.09.057
2009
Cited 38 times
The <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math> S-wave from the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo…
Using data from FOCUS (E831) experiment at Fermilab, we present a model independent partial-wave analysis of the K−π+ S-wave amplitude from the decay D+→K−π+π+. The S-wave is a generic complex function to be determined directly from the data fit. The P- and D-waves are parameterized by a sum of Breit–Wigner amplitudes. The measurement of the S-wave amplitude covers the whole elastic range of the K−π+ system.
DOI: 10.2172/1922503
2023
Cited 3 times
Report of the 2021 U.S. Community Study on the Future of Particle Physics (Snowmass 2021)
This is the full high-level report of Snowmass 2021, the most recent of the U.S. High Energy Physics (HEP) Community Planning Exercises, sponsored by the Division of Particles and Fields (DPF) of the American Physical Society (APS), with strong consultation from the aligned APS Divisions of Nuclear Physics, Astrophysics, Gravitational Physics, and Physics of Beams. The goal of these community studies, the first of which was in 1982, has been to identify the most important scientific questions in HEP for the following decade, with an eye to the decade after that, and the facilities, infrastructure, and \R&D needed to pursue them. This report consists of an overall summary, chapters on each of the ten main working groups of the study, called "Frontiers", a chapter on the work of the Snowmass Early Career Organization, a chapter on the ongoing search for dark matter as an example of cross-Frontier and cross-disciplinary physics, and a short Conclusion. Many reports and white p apers provided input to this document and they are also available on an associated website.
DOI: 10.1016/0370-2693(93)90679-c
1993
Cited 41 times
A measurement of elastic J/ψ photoproduction cross section at Fermilab E687
Measurements of elastic photoproduction cross sections for the J/ψ meson from 100 GeV to 375 GeV are presented. The results indicate that the cross section increases slowly in this range. The shape of the energy dependence agrees well with the photon-gluon fusion model prediction.
DOI: 10.1103/physrevlett.43.1691
1979
Cited 34 times
High-Energy Photoproduction of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>ρ</mml:mi></mml:mrow><mml:mrow><mml:mo>′</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mn /><mml:mo>(</mml:mo><mml:mn>1600</mml:mn><mml:mo>)</mml:mo><mml:mn /></mml:math>
A resonance is observed in the diffractively photoproduced two-pion final state with a mass of \ensuremath{\sim} 1600 MeV and a width of \ensuremath{\sim} 300 MeV. The four-pion distribution is characterized by a width of \ensuremath{\sim} 600 MeV and peaks around 1500 MeV.
DOI: 10.1016/j.physletb.2005.07.024
2005
Cited 36 times
Search for T violation in charm meson decays
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.
DOI: 10.1016/s0370-2693(02)02386-9
2002
Cited 35 times
New measurements of the D→μν form factor ratios
Using a large sample of D+ to K- pi+ mu+ nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic form factor ratios: rv and r2. We find rv = 1.504 \pm 0.057 \pm 0.039 and r2 = 0.875 \pm 0.049 \pm 0.064. Our form factor results include the effects of the s-wave interference discussed in a previous paper.
DOI: 10.1016/j.physletb.2005.06.062
2005
Cited 33 times
Hadronic mass spectrum analysis of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:math> decay and measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="…
We present a Kπ mass spectrum analysis of the four-body semileptonic charm decay D+→K−π+μ+ν in the range of 0.65GeV/c2<mKπ<1.5GeV/c2. We observe a non-resonant contribution of 5.30±0.74−0.96+0.99% with respect to the total D+→K−π+μ+ν decay. For the K∗(892)0 resonance, we obtain a mass of 895.41±0.32−0.43+0.35MeV/c2, a width of 47.79±0.86−1.06+1.32MeV/c2, and a Blatt–Weisskopf damping factor parameter of 3.96±0.54−0.90+1.31GeV−1. We also report 90% CL upper limits of 4% and 0.64% for the branching ratios Γ(D+→K¯∗(1680)0μ+ν)Γ(D+→K−π+μ+ν) and Γ(D+→K¯0∗(1430)0μ+ν)Γ(D+→K−π+μ+ν), respectively.
DOI: 10.1016/j.nima.2003.08.163
2004
Cited 32 times
The target silicon detector for the FOCUS spectrometer
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.
DOI: 10.1016/j.physletb.2005.05.020
2005
Cited 31 times
Measurement of the doubly Cabibbo suppressed decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> and a search for charm mixing
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.
DOI: 10.1016/j.nima.2005.05.069
2005
Cited 28 times
Application of genetic programming to high energy physics event selection
We review genetic programming principles, their application to FOCUS data samples, and use the method to study the doubly Cabibbo suppressed decay D+ -> K+ pi+ pi- relative to its Cabibbo favored counterpart, D+ -> K- pi+ pi+. We find that this technique is able to improve upon more traditional analysis methods. To our knowledge, this is the first application of the genetic programming technique to High Energy Physics data.
DOI: 10.1016/j.physletb.2006.01.017
2006
Cited 25 times
Study of the decay asymmetry parameter and CP violation parameter in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msubsup><mml:mi>Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:mo>→</mml:mo><mml:mi>Λ</mml:mi><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math> decay
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.
DOI: 10.1016/0370-2693(94)91351-x
1994
Cited 31 times
Observation and mass measurement of
We present evidence for the Ωc0 in a new decay mode Ωc0 → Σ+K−K−π+, for which we find 42.5 ± 8.8 events with a mass of 2699.9 ± 1.5 ± 2.5 MeV/c2. The data are from Fermilab high energy photoproduction experiment E687.
DOI: 10.2172/993204
2000
Cited 29 times
Proposal for an Experiment to Measure Mixing, CP Violation and Rare Decays in Charm and Beauty Particle Decays at the Fermilab Collider - BTeV
This proposal consists of five parts and two appendices. The first part provides a detailed physics justification for the BTe V experiment. The second part presents the considerations that drive the detector design, followed by a description of the detector itself. The third part summarizes our simulation results which demonstrate that the design does enable us to achieve our physics goals. The fourth part compares BTeV's physics reach to that of other experiments which will be active in B physics in the same time period. The fifth part gives a very brief, high level summary of the cost estimate for BTeV. Appendix A has additional technical details about many of the detector subsystems and R&D plans; it is intended to be read primarily by experts in each area. Appendix B contains a roadmap which describes the location in the proposal of the answers to questions posed to the BTeV collaboration by the Fermilab Program Advisory Committee in June of 1999.
DOI: 10.1016/s0168-9002(01)02065-4
2002
Cited 28 times
Reconstruction of Vees, Kinks, Ξ−'s, and 's in the FOCUS spectrometer
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.
DOI: 10.1016/s0168-9002(03)01862-x
2003
Cited 20 times
Precision measurement of energy and position resolutions of the BTeV electromagnetic calorimeter prototype
The energy dependence of the energy and position resolutions of the electromagnetic calorimeter prototype made of lead tungstate crystals produced in Bogoroditsk (Russia) and Shanghai (China) is presented. These measurements were carried out at the Protvino accelerator using a 1–45GeV electron beam. The crystals were coupled to photomultiplier tubes. The dependence of energy and position resolutions on different factors as well as the measured electromagnetic shower lateral profile are presented.
DOI: 10.1016/j.physletb.2003.07.079
2003
Cited 19 times
Search for rare and forbidden 3-body di-muon decays of the charmed mesons D+ and D+
Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report results of a search for eight rare and Standard-Model-forbidden decays: D+, Ds+ > h+/- muon-/+ muon+ (with h=pion or Kaon). Improvement over previous results by a factor of 1.7--14 is realized. Our branching ratio upper limit D+ > pion+ muon- muon+ of 8.8E-6 at the 90% C.L. is below the current MSSM R-Parity violating constraint.
DOI: 10.1016/s0168-9002(03)02014-x
2003
Cited 19 times
Study of radiation damage in lead tungstate crystals using intense high-energy beams
We report on the effects of radiation on the light output of lead tungstate crystals. The crystals were irradiated by pure, intense high energy electron and hadron beams as well as by a mixture of hadrons, neutrons and gammas. The crystals were manufactured in Bogoroditsk, Apatity (both Russia), and Shanghai (China). These studies were carried out at the 70-GeV proton accelerator in Protvino.
DOI: 10.1016/j.physletb.2005.02.005
2005
Cited 19 times
Study of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> decay
Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the Cabibbo-suppressed decay mode D0→K+K−π+π−. We measure: Γ(D0→K+K−π+π−)/Γ(D0→K−π−π+π+)=0.0295±0.0011±0.0008. An amplitude analysis has been performed in order to determine the resonant substructure of this decay mode. The dominant components are the decays D0→K1(1270)+K−, D0→K1(1400)+K− and D0→ρ(770)0ϕ(1020).
DOI: 10.1016/j.physletb.2005.12.003
2006
Cited 16 times
A non-parametric approach to the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mover accent="true"><mml:mi>K</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mrow><mml:mo>∗</mml:mo><mml:mn>0</mml:mn></mml:mrow></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:math> form factors
Using a large sample of D+ -> K- pi+ mu+ nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first measurements of the helicity basis form factors free from the assumption of spectroscopic pole dominance. We also present the first information on the form factor that controls the s-wave interference discussed in a previous paper by the FOCUS collaboration. We find reasonable agreement with the usual assumption of spectroscopic pole dominance and measured form factor ratios.
DOI: 10.48550/arxiv.2301.06581
2023
Report of the 2021 U.S. Community Study on the Future of Particle Physics (Snowmass 2021) Summary Chapter
The 2021-22 High-Energy Physics Community Planning Exercise (a.k.a. ``Snowmass 2021'') was organized by the Division of Particles and Fields of the American Physical Society. Snowmass 2021 was a scientific study that provided an opportunity for the entire U.S. particle physics community, along with its international partners, to identify the most important scientific questions in High Energy Physics for the following decade, with an eye to the decade after that, and the experiments, facilities, infrastructure, and R&D needed to pursue them. This Snowmass summary report synthesizes the lessons learned and the main conclusions of the Community Planning Exercise as a whole and presents a community-informed synopsis of U.S. particle physics at the beginning of 2023. This document, along with the Snowmass reports from the various subfields, will provide input to the 2023 Particle Physics Project Prioritization Panel (P5) subpanel of the U.S. High-Energy Physics Advisory Panel (HEPAP), and will help to guide and inform the activity of the U.S. particle physics community during the next decade and beyond.
DOI: 10.1016/0370-2693(95)00941-d
1995
Cited 21 times
First measurement of the lifetime of the Ω
We present the first measurement of the lifetime of the Ωc0 baryon. The data were collected in the Fermilab high energy photoproduction experiment E687. The measured lifetime is τ = 86−20+27(stat.) ± 28(syst.) fr. Thus the Ωc0 has one of the shorter lifetimes among the weakly decaying singly charmed baryons.
DOI: 10.1103/physrevlett.86.2955
2001
Cited 20 times
Study of the Decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">D</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi /><mml:mo>→</mml:mo><mml:mi /><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">K</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">π</mml:mi></mml:mrow><mml:…
Using a large sample of photoproduced charm mesons from the FOCUS experiment at Fermilab (FNAL-E831), we observe the decay D0-->K+pi- with a signal yield of 149+/-31 events compared to a similarly cut sample consisting of 36 760+/-195 D0-->K-pi+ events. We use the observed ratio of D0-->K+pi- to D0-->K-pi+ (0.404+/-0.085+/-0.025)% to obtain a relationship between the D0 mixing and doubly Cabibbo suppressed decay parameters.
DOI: 10.1016/0370-2693(91)90508-n
1991
Cited 19 times
A measurement of the D0 and D+ lifetimes
We present precision measurements of the D0 and D+ meson lifetimes using approximately 7500 fully reconstructed D0→K−π+, K−π+π+π−, D+→K−π+π+, and charge conjugate decays. The data were accumulated by the Fermilab high ene rgy photoproduction experiment E687. The lifetime of the D0 is measured to be 0.424±0.011±0.007 ps while the D+ lifetime is measured to be 1.075±0.040±0.018 ps.
DOI: 10.1103/physrevlett.50.302
1983
Cited 16 times
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>ψ</mml:mi></mml:mrow><mml:mrow><mml:mo>′</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>Photoproduction at a Mean Energy of 150 GeV
A measurement of the diffractive ${\ensuremath{\psi}}^{\ensuremath{'}}$ photoproduction cross section is presented. The ratio of the ${\ensuremath{\psi}}^{\ensuremath{'}}$ photoproduction cross section to the $\ensuremath{\psi}$ photoproduction cross section is found to be 0.20 \ifmmode\pm\else\textpm\fi{} 0.05 at an average energy of 150 GeV. With vector-meson dominance, the ratio of ${\ensuremath{\psi}}^{\ensuremath{'}}$-nucleon to $\ensuremath{\psi}$-nucleon cross sections is 0.75 \ifmmode\pm\else\textpm\fi{} 0.12.
DOI: 10.1103/physrevlett.59.2711
1987
Cited 15 times
Measurements of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>Σ</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup></mml:mrow><mml:mo>−</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>Λ</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow…
Measurements of ${\ensuremath{\Sigma}}_{c}^{0}\ensuremath{-}{{\ensuremath{\Lambda}}_{c}}^{+}$ and ${{\ensuremath{\Sigma}}_{c}}^{++}\ensuremath{-}{{\ensuremath{\Lambda}}_{c}}^{+}$ mass differences have been made in a beam of incident neutrons. Our ${{\ensuremath{\Sigma}}_{c}}^{++}\ensuremath{-}{{\ensuremath{\Lambda}}_{c}}^{+}$ mass-difference measurement is 167.4\ifmmode\pm\else\textpm\fi{}2.1 MeV/${\mathit{c}}^{2}$, in good agreement with previous results. We measure the ${\ensuremath{\Sigma}}_{c}^{0}\ensuremath{-}{{\ensuremath{\Lambda}}_{c}}^{+}$ mass difference to be 178.2\ifmmode\pm\else\textpm\fi{}2.0 MeV/${\mathit{c}}^{2}$. We use these measurements to determine the ${{\ensuremath{\Sigma}}_{c}}^{++}\ensuremath{-}{\ensuremath{\Sigma}}_{c}^{0}$ mass splitting to be -10.8\ifmmode\pm\else\textpm\fi{}2.0 MeV/${\mathit{c}}^{2}$.
DOI: 10.1016/j.physletb.2004.02.015
2004
Cited 14 times
New measurements of the D+→φμ+ν form factor ratios
Using a large sample of Ds to Phi mu nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic form factor ratios: rV and r2. We find rV = 1.549 \pm 0.250 \pm 0.145 and r2 = 0.713 \pm 0.202 \pm 0.266. These values are consistent with the rV and r2 form factors measured for the process D+ to K*bar mu nu.
DOI: 10.1016/s0168-9002(03)01860-6
2003
Cited 14 times
Development of a momentum determined electron beam in the 1– range
A beam line for electrons with energies in the range of 1–45GeV, low contamination of hadrons and muons and high intensity up to 106 per accelerator spill at 27GeV was setup at U70 accelerator in Protvino, Russia. A beam tagging system based on drift chambers with 160μm resolution was able to measure relative electron beam momentum precisely. The resolution σp/p was 0.13% at 45GeV where multiple scattering is negligible. This test beam setup provided a possibility to study properties of lead tungstate crystals (PbWO4) for the BTeV experiment at Fermilab.
DOI: 10.1016/j.physletb.2004.12.062
2005
Cited 14 times
Measurement of the branching ratio of the decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:math> relative to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mn>…
We present a new measurement of the branching ratio of the Cabibbo suppressed decay D^0\to \pi^-\mu^+\nu relative to the Cabibbo favored decay D^0\to K^-\mu^+\nu and an improved measurement of the ratio |\frac{f_+^{\pi}(0)}{f_+^{K}(0)}|. Our results are 0.074 \pm 0.008 \pm 0.007 for the branching ratio and 0.85 \pm 0.04 \pm 0.04 \pm 0.01 for the form factor ratio, respectively.
DOI: 10.1103/physrevlett.88.161801
2002
Cited 14 times
A High Statistics Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>Λ</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math>Lifetime
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.
DOI: 10.1016/j.physletb.2004.09.022
2004
Cited 12 times
Study of the doubly and singly Cabibbo suppressed decays D+ → K+π+π− and D+→K+π+π−
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.
DOI: 10.1016/s0370-2693(03)00809-8
2003
Cited 12 times
Measurements of Ξ+ branching ratios
Using data collected by the fixed target Fermilab experiment FOCUS, we measure the branching ratios of the Cabibbo-favored decays Ξc+→Σ+K−π+, Ξc+→Σ+K̄∗(892)0, and Ξc+→Λ0K−π+π+ relative to Ξc+→Ξ−π+π+ to be 0.91±0.11±0.04, 0.78±0.16±0.06, and 0.28±0.06±0.06, respectively. We report the first observation of the Cabibbo-suppressed decay Ξc+→Σ+K+K− and we measure the branching ratio relative to Ξc+→Σ+K−π+ to be 0.16±0.06±0.01. We also set 90% confidence level upper limits for Ξc+→Σ+φ and Ξc+→Ξ∗(1690)0(Σ+K−)K+ relative to Ξc+→Σ+K−π+ to be 0.12 and 0.05, respectively. We find an indication of the decays Ξc+→Ω−K+π+ and Ξc+→Σ∗(1385)+K̄0 and set 90% confidence level upper limits for the branching ratios with respect to Ξc+→Ξ−π+π+ to be 0.12 and 1.72, respectively. Finally, we determine the 90% C.L. upper limit for the resonant contribution Ξc+→Ξ∗(1530)0π+ relative to Ξc+→Ξ−π+π+ to be 0.10.
DOI: 10.1038/s42254-022-00493-9
2022
Cited 3 times
How high-energy physics plans its future
Past and present chairs of the Division of Particles and Fields of the American Physical Society explain how the high-energy physics community in the US decides the priorities for research through regular planning exercises that started 40 years ago at Snowmass, Colorado.
DOI: 10.1016/0370-2693(94)90449-9
1994
Cited 14 times
Measurement of the form factors for the decay D+s → φμ+ν
The fermilab high-energy photoproduction experiment E687 provides a sample of approximately 90 events of the decay mode D+s→ φμ+ ν. The ratios of the form factors governing the decay are measured to be Rv=1.8±0.9±0.2 and R2= 1.1±0.8±0.1, implying a polarization of Г1/Гt = 1.0±0.5±0.1 for the electron decay, consistent with our measurement of the form factor for the decay D+ → K∗0 μ+ ν.
DOI: 10.1016/s0370-2693(03)00388-5
2003
Cited 11 times
Measurement of the Ωc0 lifetime
The FOCUS experiment (FNAL-E831) has used two channels, Ω−π+ and Ξ−K−π+π+, to measure the lifetime of the Ωc0 charmed baryon. From a sample of 64±14 signal events at a mass of 2.698 GeV/c2, we measure an Ωc0 lifetime of 72±11 (stat.) ±11 (sys.) fs, substantially improving upon the current world average.
DOI: 10.1016/j.nima.2004.04.231
2004
Cited 10 times
Comparison of radiation damage in lead tungstate crystals under pion and gamma irradiation
Studies of the radiation hardness of lead tungstate crystals produced by the Bogoroditsk Techno-Chemical Plant in Russia and the Shanghai Institute of Ceramics in China have been carried out at IHEP, Protvino. The crystals were irradiated by a 40GeV pion beam. After full recovery, the same crystals were irradiated using a 137Csγ-ray source. The dose rate profiles along the crystal length were observed to be quite similar. We compare the effects of the two types of radiation on the crystal's light output.
DOI: 10.1016/0370-2693(93)90181-g
1993
Cited 13 times
Study of D0 → K− μ+ ν in high energy photoproduction
We report a measurement of the semimuonic decay D0→K−μ+ν from data taken during the 1987–1988 fixed target run at Fermilab by the E687 Collaboration. We obtain Γ(D0→K−μ+ν)/Γ(D0→K−π+)=0.82±0.13±0.13 and use this result to calculate Γ(D0→K∗−μ+ν)/Γ(D0→K−μ+ν)=0.59±0.10±0.13.
DOI: 10.1103/physrevlett.60.2117
1988
Cited 11 times
Production of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow /><mml:mrow /><mml:mrow><mml:mo>±</mml:mo></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>by High-Energy Neutrons
We have observed the production of the $D_{s}^{}{}_{}{}^{\ifmmode\pm\else\textpm\fi{}}$ by a high-energy neutron beam on nuclear targets. The $D_{s}^{}{}_{}{}^{\ifmmode\pm\else\textpm\fi{}}$ was observed in the decay mode $D_{s}^{}{}_{}{}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, $\ensuremath{\varphi}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}$. The average of the inclusive cross sections for $D_{s}^{}{}_{}{}^{+}$ and $D_{s}^{}{}_{}{}^{\ensuremath{-}}$ hadroproduction is measured to be $\frac{\mathrm{Bd}\ensuremath{\sigma}}{d{x}_{\mathrm{F}}}=2.85\ifmmode\pm\else\textpm\fi{}0.80\ifmmode\pm\else\textpm\fi{}0.86$ \ensuremath{\mu}b/nucleon at ${x}_{\mathrm{F}}=0.175$ on the assumption of a linear $A$ dependence, where $B\ensuremath{\equiv}\frac{\ensuremath{\Gamma}(D_{s}^{}{}_{}{}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})}{\ensuremath{\Gamma}(D_{s}^{}{}_{}{}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}\mathrm{all})}$.
DOI: 10.1016/0370-2693(88)90381-4
1988
Cited 11 times
Observation of D0 → K00
We have observed the decay mode D0 → KS0KS0. The signal was isolated by detecting both KS0's decaying via KS0 → π+π−, and by using the well-known D∗+ → D0 π+ mass difference. We have measured the branching fraction of D0 → KS0KS0 relative to D0 → K+K− and find the ratio Γ(D0 → K0K0)/Γ(D0 → K+K−) to be 0.4 ± 0.3.
DOI: 10.1016/j.nima.2004.06.161
2004
Cited 9 times
LED monitoring system for the BTeV lead tungstate crystal calorimeter prototype
We report on the performance of a monitoring system for a prototype calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled with photomultiplier tubes. The tests were carried out at the 70 GeV accelerator complex at Protvino, Russia.
DOI: 10.1016/j.physletb.2004.12.063
2005
Cited 8 times
A study of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msubsup><mml:mi>K</mml:mi><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:msubsup><mml:mi>K</mml:mi><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:mi>X</mml:mi></mml:math> decay channels
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.
DOI: 10.1016/j.nima.2005.10.007
2006
Cited 8 times
Design and performance of LED calibration system prototype for the lead tungstate crystal calorimeter
A highly stable monitoring system based on blue and red light emitting diodes coupled to a distribution network comprised of optical fibers has been developed for an electromagnetic calorimeter that uses lead tungstate crystals readout with photomultiplier tubes. We report of the system prototype design and on the results of laboratory tests. Stability better than 0.1% (r.m.s.) has been achieved during one week of prototype operation.
DOI: 10.1088/1748-0221/16/07/p07023
2021
Cited 4 times
Test beam characterization of sensor prototypes for the CMS Barrel MIP Timing Detector
The MIP Timing Detector will provide additional timing capabilities for detection of minimum ionizing particles (MIPs) at CMS during the High Luminosity LHC era, improving event reconstruction and pileup rejection. The central portion of the detector, the Barrel Timing Layer (BTL), will be instrumented with LYSO:Ce crystals and Silicon Photomultipliers (SiPMs) providing a time resolution of about 30 ps at the beginning of operation, and degrading to 50-60 ps at the end of the detector lifetime as a result of radiation damage. In this work, we present the results obtained using a 120 GeV proton beam at the Fermilab Test Beam Facility to measure the time resolution of unirradiated sensors. A proof-of-concept of the sensor layout proposed for the barrel region of the MTD, consisting of elongated crystal bars with dimensions of about 3 x 3 x 57 mm$^3$ and with double-ended SiPM readout, is demonstrated. This design provides a robust time measurement independent of the impact point of the MIP along the crystal bar. We tested LYSO:Ce bars of different thickness (2, 3, 4 mm) with a geometry close to the reference design and coupled to SiPMs manufactured by Hamamatsu and Fondazione Bruno Kessler. The various aspects influencing the timing performance such as the crystal thickness, properties of the SiPMs (e.g. photon detection efficiency), and impact angle of the MIP are studied. A time resolution of about 28 ps is measured for MIPs crossing a 3 mm thick crystal bar, corresponding to an MPV energy deposition of 2.6 MeV, and of 22 ps for the 4.2 MeV MPV energy deposition expected in the BTL, matching the detector performance target for unirradiated devices.
DOI: 10.1016/0370-2693(92)90180-c
1992
Cited 11 times
Study of D0→KS0π+π− and D0→KS0K+K− in high energy photoproduction
Analysis of the resonant and non-resonant branching fractions for the decays D0→KS0π+π−and D0→KS0K+K− is presented. For the D0→KS0π+π− decay, a fit to the observed Dalitz plot was performed to determine the complex amplitudes of the sub-component modes. For the D0→KS0K+K− decay, measurements of the branching ratios D0→KS0K+K− (inclusive), D0→KS0φ, and D0→KS0(K+K−)non-φ relative to the D0→KS0π+π− mode are reported. The data were collected by the Fermilab high energy photoproduction experiment E687.
DOI: 10.1016/j.nima.2005.04.090
2005
Cited 7 times
Correlation of beam electron and LED signal losses under irradiation and long-term recovery of lead tungstate crystals
Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystal recovery from such damage.
DOI: 10.1016/0370-2693(94)90450-2
1994
Cited 10 times
First observation of the Σ− π+ π+ decay mode of the Λc baryon and its branching ratio relative to the Σ+ π+ π− mode
We report the first observation (103±17 events) of the decay Λ+c → Σ−π+π+ and the charge conjugate. A measurement of the relative branching ratio Г (Λ+c → Σ−π+π+)/Г (Λ+c → Σ+π+π+π− = 0.53±0.15 (stat) ± 0.07 (sys) is also presented.
DOI: 10.1016/s0370-2693(02)02103-2
2002
Cited 8 times
Measurements of relative branching ratios of Λ+ decays into states containing Σ
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%.
DOI: 10.1016/s0168-9002(01)00369-2
2001
Cited 8 times
Beam test results of the BTeV silicon pixel detector
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.
DOI: 10.1016/s0168-9002(01)02152-0
2002
Cited 7 times
Performance of prototype BTeV silicon pixel detectors in a high-energy pion beam
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.
DOI: 10.1103/physrevlett.87.162001
2001
Cited 7 times
Measurement of the Branching Ratios of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">D</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></…
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.
DOI: 10.1016/j.physletb.2005.08.014
2005
Cited 5 times
Study of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msubsup><mml:mi mathvariant="normal">Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup></mml:math> Cabibbo favored decays containing a Λ baryon in the final state
Using data from the FOCUS experiment (FNAL–E831), we study the decay of Λc+ baryons into final states containing a Λ hyperon. The branching fractions of Λc+ into Λπ+, Λπ+π+π− and ΛK¯0K+ relative to that into pK−π+ are measured to be 0.217±0.013±0.020, 0.508±0.024±0.024 and 0.142±0.018±0.022, respectively. We also report new measurements of Γ(Λc+→Σ0π+)Γ(Λc+→Λπ+)=1.09±0.11±0.19, Γ(Λc+→Σ0π+π+π−)Γ(Λc+→Λπ+π+π−)=0.26±0.06±0.09 and Γ(Λc+→Ξ(1690)0(ΛK¯0)K+)Γ(Λc+→ΛK¯0K+)=0.32±0.10±0.04. Further, an analysis of the subresonant structure for the Λc+→Λπ+π+π− decay mode is presented.
DOI: 10.1016/j.nima.2004.11.015
2005
Cited 5 times
Study of possible scintillation mechanism damage in crystals after pion irradiation
We employed two independent methods to study possible damage to the scintillation mechanism in lead tungstate crystals due to irradiation by a 34 GeV pion beam. First, 10 crystals were irradiated simultaneously over 30 hours by a narrow beam, so that only a small region of each crystal was affected. We studied the effect of the irradiation on the light output non-uniformity. If a localized degradation was observed, it would indicate damage to the scintillation mechanism. Secondly, we detected light output using two phototubes attached to sides of a crystal. Since these phototubes detect scintillation light only from a small localized region, the effect of transmission loss should be minimal. We did not see any statistically significant evidence for scintillation mechanism damage with either method. The effect is consistent with zero, and the upper limit is 0.5% at 95% C.L.
DOI: 10.48550/arxiv.1709.03006
2017
Cited 3 times
Highlights and Perspectives from the CMS Experiment
In 2016, the Large Hadron Collider provided proton-proton collisions at 13 TeV center-of-mass energy and achieved very high luminosity and reliability. The performance of the CMS Experiment in this running period and a selection of recent physics results are presented. These include precision measurements and searches for new particles. The status and prospects for data-taking in 2017 and a brief summary of the highlights of the High Luminosity (HL-LHC) upgrade of the CMS detector are also presented.
1956
Effect of Concentration on Ignition Delays for Various Fuel-Oxygen-Nitrogen Mixtures at Elevated Temperatures
Note presenting measurements of ignition delays for mixtures of ethane, n-butane, isobutane, hydrogen, or propane with oxygen and nitrogen using a flow system with two experimental procedures. Delays were measured over a range of temperatures for each gas. Results regarding a comparison among fuels and effect of experimental procedure on absolute values of ignition delay are provided.
DOI: 10.1016/0370-2693(95)00041-i
1995
Cited 8 times
Charm meson decay into the final states K0K+ and KK
We have made a new measurement of the branching ratio Γ(D+ → K0K+)Γ(D+ → K0π+) and the first measurement of Γ(D+ → K0K∗+)Γ(D+ → K0π+). The data were accumulated in the 1990–1991 fixed target running period of Fermilab high energy photoproduction experiment E687. We measure Γ(D+ → K0K+)Γ(D+ → K0π+) = 0.25 ± 0.04 ± 0.02 and Γ(D+ → K0K∗+)Γ(D+ → K0π+) = 1.1 ± 0.3 ± 0.4.
DOI: 10.1016/0370-2693(95)01085-5
1995
Cited 7 times
Doubly and singly Cabibbo suppressed charm decays into the K+π−π+ final state
Branching ratios and upper limits at 90% confidence level for D+ and Ds+ → K+π−π+ decays collected in Fermilab photoproduction experiment E-687 are reported. The D+ results are: Γ(D+ → K+π−π+)Γ(D+ → K−π+π+) = (7.2 ± 2.3 ± 1.7) × 10−3, Γ(D+ → K∗0(892)π+)Γ(D+ → K−π+π+) < 0.0021, and Γ(D+ → K+ϱ0(770))Γ(D+ → K−π+π+) < 0.0067. The Ds+ results are: Γ(Ds+ → K+π−π+)Γ(Ds+ → Φ(1020)π+) = 0.28 ± 0.06 ± 0.05, Γ(Ds+ → K∗0(892)π+Γ(Ds+ → Φ(1020)π+) = 0.18 ± 0.05 ± 0.04, and Γ(Ds+ → K+ϱ0(770))Γ(Ds+ → Φ(1020)π+) < 0.08.
DOI: 10.1016/0370-2693(92)90292-c
1992
Cited 7 times
Measurement of the decays D0 → π+π+π−π−, D0 → K−K+ and
We present measurements of the branching ratios for two Cabibbo suppressed decays of the D0 meson, D0 → π+π+π−π− and D0 → K−K+, and for the decay D+s → фπ+π+π−. The physics signals were extracted from a data sample consisting of 60 million triggers, collected by Fermilab Photoproduction Experiment E687 from December 1987 to February 1988. The relative branching ratios are measured to be: Γ(D0 → 4π)/Γ(D0 → K3π) = 0.108±0.024±0.008, Γ(D0 → KK)/Γ(D0 → Kπ) = 0.138±0.027 ±0.010 and Γ(Ds → ф3π)/Γ(Ds → фπ) = 0.58±0.20±0.10.
DOI: 10.1016/j.nuclphysbps.2005.01.246
2006
Cited 3 times
The Electromagnetic Calorimeter of the BTeV Experiment
BTeV is a new dedicated B-physics project at Fermilab. It requires excellent photon detection which is crucial to study CP violations in B decays and rare decays of B's to explore physics beyond the standard model. Electromagnetic calorimeter (EMCAL) built of lead tungstate (PbWO4) scintillating crystals can provide excellent energy and position resolution, compact shower size, fast signal, and reasonable radiation hardness. We have carried out beam studies of a prototype of the BTeV electromagnetic calorimeter. The test took place at the Institute for High Energy Physics, Protvino, Russia. The prototype was built of 25 PbWO4 crystals, from russian and chinese manufacturers. The results of the first set of measurements have confirmed the expected good energy and position resolution of the prototype, though revealed the fact that PbWO4 was not as radiation hard as expected when irradiated with intense high energy hadron and electron beams. The next step included additional studies of radiation hardness, methods of monitoring changes of crystal signal due to radiation using LEDs with different wavelength, and possible procedures for testing PbWO4 radiation hardness without high energy beams.
DOI: 10.1016/0370-2693(94)01346-2
1994
Cited 6 times
Branching ratios of the decays and D0 → KS0KS0KS0
The branching ratios of D0 → K0K0 and D0 → Ks0Ks0Ks0 relative to D0 → K0π+π− are reported. The data were accumulated in the 1990–1991 fixed target running period of the Fermilab high energy photoproduction experiment E687. Γ (D0 → K0K0)/Γ (D0 → K0π+π− is measured to be 0.039±0.013±0.013 and Γ (D0→Ks0Ks0Ks0)/Γ (D0 → K0π+π−) is measured to be 0.035±0.012±0.006. We also measure Γ (D0 → K0π+π−/Γ (D0 → K−π+) to be 1.61±0.10±0.15.
DOI: 10.1016/s0370-2693(96)01548-1
1997
Cited 5 times
Observation of the vector meson Cabibbo suppressed decay D+ → ρ0π+ν
We report on the first statistically significant observation of the vector meson Cabibbo suppressed semileptonic decay D+ → ρ0μ+ν. We measure the branching ratio of the decay mode D+ → ρ0μ+ν (plus possible unobserved γ from D+ → η′μ+ν, η′ → γρ0) with respect to the decay mode D+ → K∗0μ+ν to be BR (D+ → ρ0μ+ν)BR (D+ → K∗0μ+ν) = 0.079 ± 0.019 (stat) ± 0.013 (syst). Data were collected by Fermilab photoproduction experiment E687.
DOI: 10.1063/1.881524
1996
Cited 5 times
Data Acquisition and Analysis in Extremely High Data Rate Experiments
The goal of elementary particle physics is to unravel the properties of matter at the deepest level—that is, to answer questions such as. What are the basic constituents of matter and how do they interact with each other? The search for the answers to such questions has led us to probe the structure of matter at ever-smaller length scales—from atomic to nuclear and now subnuclear scales. Investigating very small distance scales (below 10−13 cm) has required very high-energy particles and, consequently, the development of gigantic particle accelerators for producing such particles. (See the box on page 55.) Although these high energy accelerators are marvels of technical and scientific ingenuity, the massive amount of data they produce could not be collected, analyzed and reduced to physics results without another marvel of modern technology: the digital computer!
DOI: 10.2172/990841
2007
Fermilab Steering Group Report
The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the industrialization of ILC components in the U.S. and creating an engineering opportunity for ILC cost reductions. It offers an early and tangible application for ILC R&D in superconducting technology, attracting participation from accelerator scientists worldwide and driving forward the technology for still higher-energy accelerators of the future, such as a muon collider. To prepare for a future decision, the Fermilab Steering Group recommends that the laboratory seek R&D support for Project X, in order to produce an overall design of Project X and to spur the R&D and industrialization of ILC linac components needed for Project X. Advice from the High Energy Physics Advisory Panel will guide any future decision to upgrade the Fermilab accelerator complex, taking into account developments affecting the ILC schedule and the continuing evaluation of scientific priorities for U.S. particle physics. Fermilab should also work toward increased resources for longer-term future accelerators such as a muon collider, aiming at higher energies than the ILC would provide.
DOI: 10.1016/j.physletb.2003.11.078
2004
Study of hadronic five-body decays of charmed mesons involving K0
We study the decay of D0 and D+s mesons into five-body final states including a KS0 and report the discovery of the decay mode Ds+→KS0KS0π+π+π−. The branching ratio for the new mode is Γ(Ds+→KS0KS0π+π−π+)Γ(Ds+→KS0K−π+π+)=0.102±0.029±0.029. We also determine the branching ratio of Γ(D0→KS0π+π+π−π−)Γ(D0→KS0π+π−)=0.095±0.005±0.007 as well as an upper limit for Γ(D0→KS0K−π+π+π−)Γ(D0→KS0π+π+π−π−)<0.054 (90% CL). An analysis of the resonant substructure for D0→KS0π+π+π−π− is also performed.
DOI: 10.1016/s0168-9002(02)01486-9
2002
Cited 3 times
The BTeV electromagnetic calorimeter
Abstract The electromagnetic calorimeter for a new Fermilab collider program named BTeV is based on lead tungstate scintillating crystals (PbWO4). Various properties of crystals manufactured by Russian and Chinese companies were measured at the U70 accelerator in Protvino. A dedicated beam momentum tagging system was used to measure the energy and spatial resolution.
DOI: 10.1016/s0920-5632(03)01893-0
2003
Distributed and/or grid-oriented approach to BTeV data analysis
The BTeV collaboration will record approximately 2 petabytes of raw data per year. It plans to analyze this data using the distributed resources of the collaboration as well as dedicated resources, primarily residing in the very large BTeV trigger farm, and resources accessible through the developing world-wide data grid. The data analysis system is being designed from the very start with this approach in mind. In particular, we plan a fully disk-based data storage system with multiple copies of the data distributed across the collaboration to provide redundancy and to optimize access. We will also position ourself to take maximum advantage of shared systems, as well as dedicated systems, at our collaborating institutions.
DOI: 10.1109/nssmic.2000.949011
2002
Beam test results of the BTeV silicon pixel detector
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.
2004
The BTeV trigger and data acquisition system
The BTeV trigger inspects every beam crossing of the Fermilab Tevatron, running at a luminosity of 2 x 10{sup 32}/cm{sup 2}-s, and selects events that have ''detached vertices'' from B decays occurring downstream of the main interaction. The system uses a massively parallel system of FPGAs and microprocessors to produce a trigger decision on average every 396 ns. The trigger calculations are facilitated by the 23 Million channel pixel detector that provides the input to the trigger. Front end electronics sparsifies the remainder of event data and sends it to large, Tbyte, memory buffers that store it until the trigger decision can be made. This complex system presents special challenges in fault monitoring and power and cooling.
DOI: 10.4135/9781483331096.n69
2015
Barolo
DOI: 10.4135/9781483331096.n67
2015
Barbera
DOI: 10.1016/s0168-9002(01)01131-7
2001
Beam test of BTeV pixel detectors
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.
2011
Summary of the session on the top quark
The CDF and D0 experiments at the Fermilab Tevatron showed recent results on the production and properties of the top quark. The CMS and ATLAS experiments presented first observations of top events at the LHC. Prospects for the top physics at the LHC over the next few years were discussed. CDF and D0 have made remarkable progress in detemerining the properties of the top quark, which so far, conforms to the expectations of the SM. The sophisticated methods they have developed form the basis of the exploration that is now starting at the LHC. New methods, such as the use of boosted top quark signatures, will be necessary to realize fully the potential of the LHC for finding new high mass particles decaying to top and for searching for deviations from the SM. Prospects for the future of top quark physics are very bright.
DOI: 10.22323/1.128.0089
2011
Top quark physics session summary
DOI: 10.1121/1.4790217
2013
LOUDSPEAKER PROTECTION CIRCUIT
2012
Summary of the Session on the Top Quark
2013
Fermilab Steering Group Report
DOI: 10.1037/e506052012-331
2010
Multicultural, Assimilation, and Colorblind Interethnic Ideologies: Conceptual and Empirical Distinctions
DOI: 10.21236/ada640036
2009
Environmental Assessment of the Prather Water Line Improvement Project Otero County, New Mexico
Abstract : HAFB and the City of Alamogordo (CoA) jointly hold water rights to Bonito Lake. The purpose of the Prather waterline is to connect the CoA water system to the HAFB water system and deliver HAFB's share of the lake water rights. The Prather line consists of approximately 18,500 linear feet of fifty-year old 16 inch steel reinforced concrete cylinder pipe, buried south along Hamilton Road from U.S. Highway 54/70 to HAFB's Boles Wells Water System Annex (BWWSA). It is the only interconnection between the CoA and HAFB water systems. It is well beyond its original life expectancy, operates at reduced pressure which limits delivery volume, and breaks frequently causing lake water delivery failure. The Prather pipeline is critical infrastructure.
DOI: 10.2172/1888800
2022
Greetings from DPF and Snowmass Meeting Overview [Slides]
DOI: 10.1063/1.53242
1997
Spectroscopy and decays of charm and bottom
After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.
DOI: 10.1063/1.55091
1998
Prospects for heavy flavor physics at hadron colliders
The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the Bs meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with ‘forward’ vs ’central’ rapidity coverage.
DOI: 10.1134/s1063778807060087
2007
Expected accuracy in a measurement of the CKM angle α using a Dalitz plot analysis of B 0 → ρπ decays in the BTeV project
A precise measurement of the angle α in the CKM triangle is very important for a complete test of the Standard Model. A theoretically clean method to extract α is provided by B 0 → ρπ decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal-to-background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tree and penguin contributions, was carried out. It was shown that, in one year of data taking, BTeV could achieve an accuracy on α better than 5°.
DOI: 10.1142/9789811200380_0011
2019
Status of the CMS Experiment, Highlights and Perspectives
2007
Reviving the white Australia Policy: The Labour Movement Returns to Its Roots
The cycle of history, it seems, is extremely hard to escape. Recent controversy over temporary skilled worker migration to Australia shows remarkable similarities to similar controversy over a hundred years ago.
DOI: 10.1103/physrevlett.54.628
1985
Inclusive Production ofΩ−andΩ¯+byKL0-Carbon Interactions in the Energy Range 80-280 GeV/c
We have measured the total cross sections of ${\ensuremath{\Omega}}^{\ensuremath{-}}$ and ${\overline{\ensuremath{\Omega}}}^{+}$ forward (${x}_{\mathrm{F}}&gt;~0$) inclusive production in ${K}_{L}^{0}$-carbon interactions in the range ${E}_{{K}^{0}}=80 \mathrm{to} 280$ GeV to be 3.5\ifmmode\pm\else\textpm\fi{}1.4 and 2.4\ifmmode\pm\else\textpm\fi{}1.0 \ensuremath{\mu}b, respectively. We observe that the ${x}_{\mathrm{F}}$ distributions for both of these states are increasing from ${x}_{\mathrm{F}}=0$ to ${x}_{\mathrm{F}}\ensuremath{\approx}0.6$. The ${p}_{\ensuremath{\perp}}^{2}$ distributions are described as an exponential function in ${p}_{\ensuremath{\perp}}$ with an average ${p}_{\ensuremath{\perp}}^{2}$ of 0.540 Ge${\mathrm{V}}^{2}$/${\mathit{c}}^{2}$.
DOI: 10.1063/1.1807333
2004
Models and Methods: Can Theory Meet the B Physics Challenge?
Theory and experiment work together in the effort to obtain insight from B physics. At Beauty 2003, we held a panel discussion among eminent theorists working in this area. Below we present the motivation for this panel, the charge to the panelists, and some brief comments concerning the discussions and main conclusions.
DOI: 10.1007/bf02823596
1994
New results on heavy-flavor photoproduction from the E687 experiment at FNAL
DOI: 10.1016/j.nuclphysbps.2005.01.080
2005
Conference Summary: 6th International Conference on Hyperons, Charm, and Beauty Hadrons (BEACH04)
The 6th International Conference on Hyperons, Charm, and Beauty Hadrons (BEACH04) treated us to a wonderful array of new results. Here I attempt to summarize the talks and discuss the conference highlights.
2005
Measurement of the branching ratio of the decay D-0 ->pi(-)mu(+)nu relative to D-0 -> K-mu(+)nu
2005
The Work Choices Bill and Its Critics
Two things are particularly disappointing about recent commentary in response to the release of the government's Work Choices bill. The first is the lack of balance in the academic 'discussion', and the second is the rather poor level of the criticism that has been levelled against the bill generally. One gets the feeling that in a desperate flurry to try and find something (anything!) to criticise, the bottom of the barrel is well and truly being scraped.
DOI: 10.1063/1.1604075
2003
Triggering and Data Acquisition General Considerations
We provide a general introduction to trigger and data acquisition systems in High Energy Physics. We emphasize the new possibilities and new approaches that have been made possible by developments in computer technology and networking.