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Measurement of the B{sup +} and B{sup 0} meson lifetimes using exclusive B {yields} {psi}K decays at CDF

Description: The authors present recent CDF measurements of {tau}{sup +}, {tau}{sup 0}, and {tau}{sup +}/{tau}{sup 0} using exclusive B {yields} {psi}K decays, where B = B{sup +} or B{sup 0}, {psi} = J/{psi} or {psi}(2S), and K = K{sup +}, K*(892){sup 0}, K{sub S}{sup 0}, or K*(892){sup +}. The precision of these results is less than 10% and is nearly identical to that previously reported at LEP.
Date: July 1995
Creator: Abe, F.
Partner: UNT Libraries Government Documents Department

Search for new phenomena in CDF-I: Z{prime}, W{prime} and leptoquarks

Description: We present the latest results of CDF searches for Z{prime}, W{prime} and leptoquarks. Using about 70pb{sup -1} data from 1992-95 CDF runs, we have searched for Z{prime} {yields} l{sup +}l{sup -}, W{prime} {yields} WZ and pairs of second generation scalar leptoquark, S{sub 2}. We find no evidence for these new particles, and set new mass limits at 95% CL. We exclude M{sub Z{prime}} < 650 GeV/c{sup 2}, 205 < M{prime}{sub W} < 400 GeV/c{sup 2}, and M{sub S2} < 180 GeV/c{sup 2} for {beta} = 1 and M{sub S2} < 141 GeV/c{sup 2} for {beta} = 0.5. Two interesting strange events are also shown.
Date: July 1, 1995
Creator: Park, S.
Partner: UNT Libraries Government Documents Department

HTS wire irradiation test with 8 GeV protons

Description: The radiation level at High Energy Particle Accelerators (HEPA) is relatively high. Any active component which should be close to the accelerator has to be radiation hard. Since High Temperature Superconductors (HTS) have a great potential to be used in HEPAs (e.g., in superconducting magnets, current leads, RF cavities), it is important to understand the radiation hardness of these materials. A radiation test of HTS wire (Bi-2223) was performed at Fermilab. The HTS sample was irradiated with 8 GeV protons and the relative I{sub c} was measured during the irradiation. The total radiation dose was 10 Mrad, and no I{sub c} degradation was observed.
Date: November 2, 1999
Creator: Feher, S.; Glass, H.; Huang, Y.; Limon, P.J.; Orris, D.F.; Schlabach, P. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the CP violation parameter sin(2{beta}) in B{sup 0} {r_arrow}J/{psi} K{sub s}{sup 0} Decays

Description: A sample of {approximately} 400 B{sub d}{sup 0}/{bar B}{sub d}{sup 0} {r_arrow} J/{psi}K{sub s}{sup 0} decays collected in {bar p}p collisions by the CDF detector is used to directly measure the CP-violation parameter sin (2{beta}). They find sin(2{beta}) = 0.79{sub {minus}0.44}{sup + 0.41}, favoring the standard model expectation of a large CP violation in this B{sup 0} decay mode.
Date: September 2, 1999
Creator: Bauer, G.
Partner: UNT Libraries Government Documents Department

Field shape of the accumulator LDA dipoles

Description: Large Aperture Dipoles (LDA) are used in the Fermilab Antiproton Accumulator to provide one half of the bending required for that storage ring. The production measurement data for those magnets are analyzed and the integrated field shape on the median plane at the design operating current (1,180 A) is reported. When linear (quadrupole) and parabolic (sextupole) terms are subtracted, the remaining field errors are only {approximately}10{sup {minus}4} over a {+-}4 inch aperture. Polynomial fits to that data can be interpreted in terms of normal harmonics of the magnetic field. However the polynomial fits are not unique. When the polynomial coefficients are expressed as harmonics with a reference radius of 1 inch, the nonlinear portions of this field (harmonics higher than quadrupole) are typically 10{sup {minus}5} to 10{sup {minus}6}. Both individual magnet results and statistical profiles are reported along with studies of the fitting limitations.
Date: May 1, 1996
Creator: Brown, B.C.
Partner: UNT Libraries Government Documents Department

Overview of coupled bunch active damper systems at FNAL

Description: Beam intensities in all of the accelerators at Fermilab will increase significantly when the Main Injector becomes operational and will cause unstable oscillations in transverse position and energy. Places where the coupled bunch oscillations could dilute emittances include the Booster, Main Injector, and Tevatron. This paper provides an overview of the active feedback system upgrades which will be used to counteract the problem. It will explain the similarities between all the systems and will also explain design differences between longitudinal and transverse systems, fast sweeping systems, and systems for partially filled machines. Results from operational systems will also be shown. 7 refs., 4 figs., 1 tab.
Date: May 1, 1996
Creator: Steimel, J.; Crisp, J.; Ma, Hengjie; Marriner, J. & McGinnis, D.
Partner: UNT Libraries Government Documents Department

Control system for Fermilab`s low temperature upgrade

Description: Fermilab recently upgraded the Tevatron Cryogenic Systems to allow for lower temperature operation. This Lower Temperature Upgrade grew out of a desire to increase the Colliding Beam Physics energy from 900 GeV to 1000 GeV. A key element in achieving this goal is the new cryogenic control system designed at Fermilab and installed in 24 satellite refrigerators and 8 compressor buildings. The cryogenic improvements and addition hardware like cold compressors exceeded the capability of the original distributed controls package. The new distributed controls package uses a Multibus II platform and Intel`s 80386 microprocessor. Token Ring is used as the link to the systems 6 primary crate locations with Arcnet used as the connection to the systems numerous I/O crates. I/0 capabilities are double the capabilities of the original system. Software has also been upgraded with the introduction of more flexible control loop strategies and Finite State Machines used for automatic sequential control, like quench recovery or cold compressor pump down.
Date: September 1, 1996
Creator: Norris, B.L.
Partner: UNT Libraries Government Documents Department

Upgrade plans for the D0 calorimeter

Description: The D{null} detector, a large collider detector located at the Fermi National Accelerator Laboratory, has begun implementing a major detector upgrade in anticipation of the completion of the Main Injector project at the Fermilab Tevatron. The calorimeter readout has been redesigned in order to accommodate the factor of {approx} 10 increase in instantaneous luminosity and the decrease in the inter- bunch separation. Our means of dealing with the increased event rate, along with our plan for controlling overall noise levels in the calorimeter, are discussed. We also present a brief overview of the design for the detector upgrade, including a discussion of some on the more cogent physics topics that will be accessible with the factor of {approx} 20 increase over the present data sample.
Date: August 1, 1996
Creator: Kotcher, J.
Partner: UNT Libraries Government Documents Department

The pixel microtelescope

Description: We describe a vertex and/or tracking detector designed to operate in an environment in which there is a large density of background hits. 2 refs., 2 figs.
Date: October 1, 1996
Creator: Chapman, J. & Geer, S.
Partner: UNT Libraries Government Documents Department

Experience with small turbomachinery in a 400 watt refrigerator

Description: A refrigerator similar to one of the Fermilab Tevatron satellites was reconfigured to use turbomachinery instead of the reciprocating equipment typical of the installations. A Sulzer dry turboexpander, Creare wet turboexpander, and IHI centrifugal cold compressor have been installed and operated for about 8000 hours. Experience was gained both with the rotating machinery and with the refrigerator itself as it interfaced with the load. Equipment was set up to regulate in the same manner as the reciprocating devices had. Heat load and operating mode were adjusted and evaluations made regarding the behavior of the devices. Individual equipment performance is described as well as system behavior and overall integration of the machinery. In particular, attention is paid to the Creare wet turboexpander. This device is operated for the first time as part of a full scale refrigeration system, testing not only its performance at the design point but also its off design characteristics and behavior in transient situations.
Date: September 1, 1996
Creator: Fuerst, J.D.
Partner: UNT Libraries Government Documents Department

Search for double parton scattering in the 4 jet channel at D0

Description: We have searched for double parton scattering in the 4-jet channel with an integrated luminosity of 4.4 pb{sup -1}, collected using the D{O} detector during 1994-1995 Fermilab Collider run at a center of mass energy ({radical}s) of 1.8 TeV. We present the preliminary observation of a statistically significant excess of signal.
Date: September 1, 1996
Creator: Yu, Yeonsik
Partner: UNT Libraries Government Documents Department

Study of the WW{gamma} and WWZ interactions at D0

Description: The {ital WW}{gamma} and {ital WWZ} gauge boson couplings have been studied through the direct observation of diboson final states produced in {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV. The total cross section for {ital W}{sub {gamma}} final states, for photons with {ital p}{sub T}{sup {gamma}} {gt} 10 GeV/c and {ital R}{sub {ital l}{gamma}} {gt} 0.7, times branching ratio of {ital W} bosons to leptons, has been measured to be 12.10{sub -1.62}{sup +1. 76}{+-}1.72 pb, in agreement with the Standard Model expectation. An upper limit of 17 pb on the total {ital WW} cross section has been set. The analysis of {ital W}{sub {gamma}} events has allowed us to set 95% confidence level (CL) limits on the anomalous {ital WW}{sub {gamma}} coupling parameters of -0.96 {lt} {Delta}{kappa} {lt} 0.98 and -0.32 {lt} {lambda} {lt} 0.30. this measurement excludes the U(1){sub EM}- only coupling between the photon and the {ital W} boson at the 96% CL. Similar measurements of the coupling parameters have been performed using {ital WW} final states.
Date: August 1, 1996
Creator: Kelly, M.L. & Collaboration, DO
Partner: UNT Libraries Government Documents Department

D0 papers on B-physics submitted to DPF '96: b-quark inclusive cross sections and b anti-b correlations using dimuons from the D0 experiment; Single muon production in the forward region at {radical}s=1.8 TEV; Rapidity dependence of the inclusive J{psi} production in the forward region {radical}s=1.8 TEV; A search for b {r_arrow} X{mu}{sup +}{mu}{sup {minus}} and B{sup 0} {r_arrow} {mu}{sup +}{mu}{sup {minus}} decays in p anti-p collisions at {radical}s=1.8 TEV

Description: Paper 1: Using dimuons collected with the D0 detector during the 1993--1995 Tevatron collider run, the authors have measured the b-quark cross section and b{anti b} correlations as given by the difference in azimuthal angle between the two muons. Both measurements agree with the NLO QCD predictions within experimental and theoretical errors. (Three other papers are included in this report.)
Date: November 1996
Creator: Vititoe, D. L.; Kozelov, Alexander; Jesik, Richard & Collaboration, D0
Partner: UNT Libraries Government Documents Department

An imaginary-{gamma}{sub t} lattice with dispersion-free straights for the 50 GeV high-intensity proton synchrotron

Description: During polarized beam experiments, the 50 GeV proton synchrotron, proposed by the Institute of Nuclear Study of Japan, requires zero-dispersion straight sections. This will be implemented by turning on a special excitation of the quadrupoles resulting in a dispersion wave through the arcs of the machine. Aside from the inconvenience of the power supply, this special excitation also brings about unwanted high betatron functions and high dispersion functions, which will eventually limit the performance of the accelerator at high intensities. In this paper, dispersion suppressors are introduced. A new preliminary lattice that contains two straight sections with nonzero dispersion and two straight sections with zero dispersion is presented. The whole ring remains having a reasonable imaginary {gamma}{sub t}. The horizontal and vertical betatron functions have been kept to below 32.4 m and dispersion function between -0.52 and 1.86 m. The number of 6.2 m dipoles is reduced from 96 to 92, and the dipole field at 50 GeV will become slightly above 18 T. Some analysis of the new lattice is discussed. 10 refs., 9 figs., 1 tab.
Date: February 1, 1997
Creator: Ng, K.-Y.
Partner: UNT Libraries Government Documents Department

Experimental results of neutron fluence outside an iron shield in the forward direction

Description: Analyses of both lateral shielding measurements and Monte Carlo calculations for beam stop geometry for incident hadrons at energies between 10 GeV and 10 TeV suggests that the dose equivalent can be represented by the expression H = H{sub 0}(E)e{sup -r/{lambda}}/r{sup 2} where H, is the source term, r is the radial distance to the point of interest in the shield, and {lambda} is the effective interaction length, or absorption mean free path. However, unlike the lateral shielding case, there is no similarly simple analytical expression that can be used to describe the on-axis longitudinal cascade development. In this study the results from the measurement in the forward direction of neutron fluence spectra (and the derived quantity dose equivalent) for 25 to 150 GeV pions incident on an iron beam stop as a function of thickness of iron are presented. The observed dependence of both fluence and dose equivalent on shield thickness and hadron energy was then quantified in terms of an expression in which a build up factor as well as an attenuation term was included. On the basis of this analysis the conversion factor from fluence to dose equivalent was also determined for these forward going neutrons. This work represents the first systematic study at an high energy accelerator of the depth dependence of neutron fluence in longitudinal shielding.
Date: September 1, 1996
Creator: Torres, M.M.C.; Elwyn, A.J.; Fein, D.; James, E.; Johns, K.; Davis, W. et al.
Partner: UNT Libraries Government Documents Department

New technologies for a future superconducting proton collider

Description: New more economic approaches are required to continue the dramatic exponential rise in particle accelerator energies as represented by the well- known Livingston plot. The old idea of low-cost, low-field iron dominated magnets in a small diameter pipe may become feasible in the next decade with dramatic recent advances in technology: (1) high T{sub c} superconductors operating at liquid N{sub 2} or H{sub 2} temperatures, (2) advanced tunneling technologies for small diameter, non human accessible tunnels, (3) accurate remote guidance systems for boring machine steering, (4) industrial applications of remote manipulation and robotics, and (5) digitally multiplexed electronics to minimize cables There is an opportunity for mutually beneficial partnerships between the High Energy Physics community and the commercial sector to develop the necessary technology. This will gain public support, a necessary part of the challenge of building a new, very high energy collider.
Date: June 1, 1996
Creator: Malamud, E. & Foster, G.W.
Partner: UNT Libraries Government Documents Department

First results from bent crystal extraction at the Fermilab Tevatron

Description: First results from Fermilab Experiment 953 are presented. E853 is an experiment to test the feasibility and efficiency of extracting a low intensity beam from the halo of the Tevatron using channeling in a bent silicon crystal. The motivation for the experiment is to apply crystal extraction to trans-TeV accelerators like the LHC. Extensive simulation work has been carried out. Two accelerator operating modes have been developed for crystal studies, ``kick`` mode and diffusion mode. Results from the first successful extraction in kick mode are presented.
Date: July 1, 1996
Creator: Collaboration, The E853
Partner: UNT Libraries Government Documents Department

In situ calibration of the CMS HCAL detector

Description: One serious challenge for hadron calorimeters is setting the absolute calibration. Electromagnetic calorimeters in a magnetic spectrometer have the momentum of electrons to calibrate against. In addition, at hadron colliders, Z supplies a narrow resonance to determine calibrations. No such well-measured processes have been available in the past for hadron calorimeters. In high energy collisions, high Pt hadrons are not normally isolated, rather appearing as part of jets. Contamination of the energy scale by unmeasured neutrals or by leakage from adjacent particles is always a concern. There are low cross section processes that possess jets of well understood energy, for example a high pt Z recoiling off of a single jet. The high energy and luminosity of the LHC may supply enough of these events for quantities useful for calibration. In this paper we outline the possibility for doing in situ calibration using Z recoiling off of a jet events, and {ital t{anti t}} events. We also comment on the more conventional possibilities of using muons and energy-flow to calibrate.
Date: December 20, 1996
Creator: Freeman, J. & Wu, W.
Partner: UNT Libraries Government Documents Department

Search for high mass photon pairs in p{anti p} collisions at {radical}s = 1.8 TeV

Description: The authors present results of a search for diphoton resonances produced inclusively and in association with a vector boson using 100 pb{sup {minus}1} of p{anti p} collisions using the CDF detector. They set upper limits on the product of cross section times branching ratio for p{anti p} {r_arrow} {gamma}{gamma} {r_arrow} X and p{anti p} {r_arrow} {gamma}{gamma} {r_arrow} W/Z. Using a NLO prediction for associated production cross section of a Higgs with a vector boson (W or Z), they set an upper limit on the branching ratio for H {r_arrow} {gamma}{gamma}. They set a lower limit on the mass of a `bosophilic` Higgs boson (e.g. one which couples only to {gamma}, W, and Z bosons with Standard Model couplings) of 82 GeV/c{sup 2} at 95% C.L.
Date: June 29, 1998
Creator: Wilson, P. J.
Partner: UNT Libraries Government Documents Department

Fully reconstructed B-meson decays using J/{psi} and {psi}(2S)

Description: In this paper we present CDF B-meson branching ratio results involving color-suppressed {ital B} {r_arrow} {Psi}{Kappa} decays, where {Psi} = {ital J}/{psi}, {psi}(2{ital S}) and {Kappa} = {Kappa}, {Kappa}{sup *}. Fully reconstructed decays of {ital B} {r_arrow} {ital J}/{psi}{Kappa}, {ital B} {r_arrow} {psi}(2{ital S}){Kappa}, {ital B}{sup +} {r_arrow} {ital J}/{psi}{pi}{sup +} and {ital B}{sub s} {r_arrow} {ital J}/{psi}{phi} are used to extract branching ratios, vector-pseudoscalar ratios and polarization parameters.
Date: September 1, 1996
Creator: Miao, Ting
Partner: UNT Libraries Government Documents Department

Recent D0 results on Z{gamma} production

Description: We report on a new search for anomalous {ital ZV}{sub {gamma}} ({ital V = Z}, {gamma}) couplings in the {ital Z}({ital ee}){gamma} mode with 89 pb{sup -1} of data. The following limits on anomalous coupling parameters were set at 95% CL: {vert_bar}{ital h{sup V}}{sub 10, 30}{vert_bar} {lt} 1.9, {vert_bar}{ital h{sup V}}{sub 20, 40}{vert_bar} {lt} 0.4. We also report on the first measurement of {ital Z(vv)}{gamma} production at hadron colliders using 14 pb{sup - 1} of data. Sensitivity to anomalous couplings in this channel is twice as good as that for the combined electron and muon channel analysis reported earlier. We set the following 95% CL limits on the {ital ZV}{gamma} couplings: {vert_bar}{ital h{sup V}}{sub 10, 30}{vert_bar} {lt} 0.9, {vert_bar}{ital h{sup V}}{sub 20, 40}{vert_bar} {lt} 0.2 which are the tightest available at the present time.
Date: November 1996
Creator: Landsberg, G.
Partner: UNT Libraries Government Documents Department

W`, Z`, leptoquarks and bump hunting at the Tevatron

Description: This paper summarizes recent results on non-SUSY searches at the Fermilab Tevatron p{bar p} collider. All the analysis are based on the complete data samples recorded by both the CDF and D0 collaborations during the 1992-1995 running period (Run 1), and correspond to {approx} 100 pb{sup -1}. Searches for new neutral heavy vector bosons, leptoquarks, dijet mass resonances, and associated production of new heavy scalars together with vector bosons show no evidence for new physics. Consequently, the results have been interpreted in terms of 95% confidence level limits on production cross sections and new particle masses.
Date: May 1, 1997
Creator: Valls, J.A. & Collaboration, The CDF and DO
Partner: UNT Libraries Government Documents Department

Color coherence in p pbar collisions at squareroot s = 1.8 TeV

Description: We report on two preliminary studies of color coherence effects on {ital p}{ital {anti p}} collisions based on data collected by the D{null} detector during the 1992-1993 and 1994-1995 runs at the Fermilab Tevatron collider at a center of mass energy {radical}s = 1. 8 TeV. Demonstration of initial-to-final state color interference effects is done in a higher energy region by measuring spatial correlations between the softer third jet and the second leading- {ital E}{sub {ital T}} jet in multi-jet events and in a lower energy regime by examining particle distribution patterns in W+Jet events. The data are compared to Monte Carlo simulations with different color coherence implementations and the predictions of an NLO parton level calculation.
Date: September 1, 1996
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department