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QCD sum rule calculation of {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0} transition form factor

Description: The authors develop a QCD sum rule analysis of the form factor F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(q{sup 2},Q{sup 2}) in the region where virtuality of one of the spacelike photons is small q{sup 2} {much_lt} 1 GeV{sup 2} while another is large: Q{sup 2} {approx_gt} 1 GeV{sup 2}. They construct the operator product expansion suitable for this kinematic situation and obtain a QCD sum rule for F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(0, Q{sup 2}). Their results confirm expectation that the momentum transfer dependence of F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(0,Q{sup 2}) is close to interpolation between its Q{sup 2}=0 value fixed by the axial anomaly and Q{sup {minus}2} pQCD behavior for large Q{sup 2}. Their approach, in contrast to pQCD, does not require additional assumptions about the shape of the pion distribution amplitude {var_phi}{sub {pi}}(x). The absolute value of the 1/Q{sup 2} term obtained in this paper favors {var_phi}{sub {pi}}(x) close to the asymptotic form {var_phi}{sub {pi}}{sup as}(x) = 6f{sub {pi}}x(1{minus}x).
Date: November 1, 1995
Creator: A.V.Radyushkin & R.T.Ruskov
Partner: UNT Libraries Government Documents Department

The D0 Upgrade

Description: In this paper we describe the approved DO Upgrade detector, and its physics capabilities. The DO Upgrade is under construction and will run during the next Fermilab collider running period in early 1999 (Run II). The upgrade is designed to work at the higher luminosities and shorter bunch spacings expected during this run. The major elements of t he upgrade are: a new tracking system with a silicon tracker, scintillating fiber tracker, a 2T solenoid, and a central preshower detector; new calorimeter electronics; new muon trigger and tracking detectors with new muon system electronics; a forward preshower detector; new trigger electronics and DAQ improvements to handle the higher rates.
Date: July 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Diphoton production in p{bar p} collisions at {radical}s = 1.8 TeV

Description: We present measurements of the inclusive {gamma}{gamma} cross section (as a function of invariant mass and photon {epsilon}{sub {tau}}), in p{bar p} collisions at {radical}s = 1.8 TeV, made using the D0 detector at the Fermilab Tevatron collider. The next is leading order (NLO) QCD prediction is found to be in good agreement with the data. The effects of invariant mass and diphoton balance cuts, which test the next-to-leading order contributions to the cross section, are investigated. We also compare the distribution of {kappa}{sub {tau}} between samples of diphotons and highly electromagnetic jets, and find that the NLO QCD prediction models the shape of the {gamma}{gamma} {kappa}{sub {tau}} distribution quite well.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Inclusive muon and b quark production cross sections in p{bar p} collisions at {radical}s = 1.8 TeV

Description: We report on the measurement of inclusive muon and b quark production by the D0 collaboration in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron Collider. The results represent a refined analysis of the previously published 1992--93 data. We measure the muon cross section due to b quark decays over the kinematic range 4 < p{sub T}{sup {mu}} < 30 GeV/c and {vert_bar}y{sup {mu}}{vert_bar} < 0.8. The extracted b quark production cross section is consistent with next to leading order QCD predictions within theoretical and experimental errors. The improved inclusive b quark production cross section is 6.9 {plus_minus}0.1(stat) {plus_minus} 2.2(syst) {mu}b for p{sub T}{sup {mu}} > 6 GeV/c and {vert_bar}y{sup b}{vert_bar} < 1.0.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Limits on the anomalous ZZ{gamma} and Z{gamma}{gamma} couplings in p{anti p} collisions at {radical}s = 1.8 TeV

Description: The authors performed a direct search for the anomalous ZZ{gamma} and Z{gamma}{gamma} couplings by studying p{anti p} {yields} {ell}{ell}{gamma} + X, ({ell} = e, {mu}) events at {radical}s = 1.8 TeV with the D0 detector at the Fermilab Tevatron Collider. A fit to the transverse energy spectrum of the photon in the signal events, based on the data set corresponding to an integrated luminosity of 14.3 pb{sup {minus}1} (13.7 pb{sup {minus}1}) for the electron (muon) channel, yields the following 95% confidence level limits on the anomalous CP-conserving ZZ{gamma} couplings: {vert_bar}h{sub 30}{sup Z}{vert_bar} < 1.8 (h{sub 40}{sup Z} = 0), and {vert_bar}h{sub 40}{sup Z}{vert_bar} < 0.5 (h{sub 30}{sup Z} = 0), for a form-factor scale {Lambda} = 500 GeV. Limits for the Z{gamma}{gamma} couplings and CP-violating couplings are also discussed.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Rapidity correlations between high p{sub T} intermediate vector bosons and jets in {bar p}p collisions at {radical}s = 1.8 TeV

Description: D{O} has used W {yields} e{nu} and Z {yields} e{sup +}e{sup -} events produced in association with a high p{sub T}, jet to examine the effects of strong radiative corrections. We have compared the primary jet pseudorapidity distribution, as a function of reconstructed W or Z boson rapidity to leading order (LO) and Next-to-Leading order (NLO) QCD Monte Carlo generators, as well as a model based on extended color dipoles. We find that the primary jet is more central than either LO or NLO expectations. None of the Monte Carlo programs does a good job of predicting the shape of the jet distributions as a function of intermediate vector bosons rapidity.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Rapidity dependence of the inclusive J/{Psi} production in p{bar p} collisions at {radical}s = 1.8 TeV

Description: We have studied J/{psi} production in p{bar p} collisions at {radical}s = 1.8 TeV with the D0 detector at Fermilab, using a {mu}{sup +}{mu}{sup {minus}} data sample collected during the 1994--1995 collider run. We have measured the inclusive J/{psi} production cross section as a function of the J/{psi} transverse momentum, p{sub T}{sup J/{psi}}, in the central and forward rapidity regions. The cross section d{sigma}/dp{sub T}{sup J/{psi}} for {vert_bar}{eta}{sup J/{psi}}{vert_bar}<0.6 covers the p{sub T}{sup J/{psi}} range from 8 to 20 GeV/c. The new measurements are in a good agreement with the CDF and earlier D0 results. The cross section d{sigma}/dp{sub T}{sup J/{psi}} for 2.6 <{vert_bar}{eta}{sup J/{psi}}{vert_bar}<3.4 covers the p{sub T}{sup J/{psi}} range from 3 to 12 GeV/c. We combine the measurements in the two {vert_bar}{eta}{sup J/{psi}}{vert_bar} regions to calculate d{sigma}/d{eta}{sup J/{psi}} for p{sub T}{sup J/{psi}} > 8 GeV/c. The data are compared with the next-to-leading (NLO) QCD calculations, which take into account different J/{psi} production mechanisms.
Date: November 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Rapidity gaps between jets at D0

Description: Results are presented from an analysis of the particle multiplicity distribution between high transverse energy jets produced at the Fermilab Tevatron p{bar p} Collider at {radical}s = 1.8 Tev. Using the D0 detector, we examine the particle multiplicity distribution between the two highest transverse energy jets. For events with large rapidity separation, we observed a significant excess of events at low tagged-particle multiplicity which is consistent with a strongly interacting color-singlet exchange process.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Search for anomalous WW and WZ production at D0

Description: We present a preliminary result from a search for anomalous WW and WZ production in p{bar p} collisions at {radical}s = 1.8 TeV using p{bar p} {yields} e{nu}jj events observed during the 1992-1993 run of the Fermilab Tevatron collider. A fit to the p{sub T} spectrum of W(e{nu}) yields direct limits on the CP-conserving anomalous WW{gamma} and WWZ coupling parameters of -0.89 < {Delta}{kappa} < 1.07 ({lambda} = 0) and -0.66 < {lambda} < 0.67 ({Delta}{kappa} = 0) at the 95% confidence level, assuming that the WWZ coupling parameters are equal to the WW{gamma} coupling parameters, and a form factor scale {Lambda} = 1.5 TeV.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Search for light top squarks with the D{O} detector

Description: We present preliminary results of a search for pair produced top squarks, the supersymmetric partners to the top quark, under the assumption that the two-body decay {bar t}{sub 1} {yields} b{bar W}{sub 1} and three-body decay {bar t}{sub 1} {yields} bW{bar Z}{sub 1} are kinematically forbidden. This scenario is realized if {bar t}{sub 1} is considerably lighter than all other squarks as well as {bar W}{sub 1}, all {bar v}s, and the top quark. Such light top squarks will dominantly decay via {bar t}{sub 1} {yields} c{bar Z}{sub 1} yielding a signal of two acollinear jets with (E){sub T}. The data reported here were taken during the 1992-1993 run of the D0 detector at the Fermilab Tevatron p{bar p} collider operating at {radical}s = 1.8 TeV.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Search for W boson pair production in p{bar p} collisions at {radical}s = 1.8 TeV

Description: The results of a search for W boson pair production in p{bar p} collisions at {radical}s = 1.8 TeV with subsequent decay to dilepton (e{mu}, ee, and {mu}{mu}) channels are presented. One event is observed with an expected background of 0.56 {plus_minus} 0.13 events with an integrated luminosity of approximately 14 pb{sup {minus}1}. Assuming equal strengths for the WWZ and WW{gamma} gauge boson coupling parameters {kappa} and {lambda}, limits on the CP-conserving anomalous coupling constants are {minus}2.6 < {delta}{kappa} < 2.8 and {minus}2.1 {lambda} < 2.1 at the 95% confidence level.
Date: July 19, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Studies of topological distributions of the three- and four-jet events in {bar p}p collisions at {radical}s = 1800 GeV with the D0 detector

Description: The global topologies of three- and four-jet events produced in {bar p}p interactions are described. the three- and four-jet events are selected from data recorded by the D0 detector at the Tevatron Collider operating at a center-of-mass energy of {radical}s = 1800 GeV. the measured normalized distributions of various topological variables are compared with parton-level predictions of the tree- level QCD calculations. The parton-level QCD calculations are found to be in good agreement with the data. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

A study of the strong coupling constant using W+ jets processes

Description: The ratio of the number of W + 1 jet to W + 0 jet events is measured with the D0 detector using data from, the 1992--93 Tevatron Collider run. For the W {yields} e{nu} channel with a minimum jet E{sub T} cutoff of 25 GeV, the experimental ratio is 0.065 {+-} 0.003(stat) {+-} 0.007(sys). Next-to-Leading order QCD predictions for various parton distributions agree well with each other and are all over one standard deviation below the measurement. Varying the strong coupling constant {alpha}{sub s} in both the parton distributions and the partonic cross sections simultaneously does not remove this discrepancy.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Tests of QCD in W and Z production at Tevatron

Description: We present measurements of the production cross sections times leptonic branching fractions and the transverse momentum distributions of W and Z bosons in p{bar p} collisions at {radical}s = 1.8 TeV using data collected with the DO detector at the Fermilab Tevatron p{bar p} collider. A preliminary measurement of the W charge asymmetry is also presented.
Date: August 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Transverse energy distributions within jets in p{anti p} collisions at {radical}s = 1.8 TeV

Description: The distribution of the transverse energy in jets has been measured in p{anti p} collisions at {radical}s = 1.8 TeV using the D0 detector at Fermilab. This measurement of the jet shape is made as a function of jet transverse energy in both the central and forward rapidity regions. Jets are observed to narrow both with increasing transverse energy and with increasing rapidity. Next-to-leading order partonic QCD calculations are compared to the data. Although the calculations qualitatively describe the data, they are shown to be very dependent on renormalization scale, parton clustering algorithm and jet direction definition and fail to consistently describe the data in all regions.
Date: July 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Single photon, photon-jet and diphoton production at DO

Description: Results are described on the observation of isolated single photons by the DO detector at the Fermilab {anti p}p collider. The inclusive cross section has been measured for photons in the central rapidity region ({vert_bar} {eta} {vert_bar}< 0.9) above 10 GeV E{sub T}. Studies of jets recoiling against the single photon permit the measurement of the fundamental hard scattering cos{theta}* distribution. An analysis of the {eta} correlations between high-E{sub T} photons and the leading jet probes the gluon x distribution. Diphoton production measurements are used both as a test of QCD processes and as a search for resonant structure, including bosonic Higgs production.
Date: July 1, 1995
Creator: Abachi, S. & Collaboration, DO
Partner: UNT Libraries Government Documents Department

Search for first and second generation leptoquarks at D0

Description: A search for first and second generation pair produced scalar leptoquarks has been done with the DO detector at Fermilab`s p{bar p} machine with {radical}s = 1.8 TeV. Leptoquarks are assumed to be strictly generational; for example, a first generation leptoquark couples only to the electron, its neutrino, and the u and d quarks. 95% C.L. mass limits of 133 GeV/c{sup 2} and 120 GeV/c{sup 2} for respective 100% and 50% decay branching ratios to electron plus quark for first generation scalar leptoquarks have been published. The preliminary results of a search for second generation scalar leptoquarks in the absence of a signal are mass limits of 111 GeV/c{sup 2} and 89 GeV/c{sup 2} for 100% and 50% decay branching ratios to muon plus quark. A feature of these mass limits is that they are independent of the unknown coupling of the leptoquark to leptons and quarks. The detection for e{sup +}e{sup {minus}} and e-p machines depends on the strength of this coupling.
Date: July 1, 1995
Creator: Abachi, S.; Abbott, B. & Abolins, M.
Partner: UNT Libraries Government Documents Department

Search for fourth generation neutral heavy leptons

Description: A search for fourth generation neutral heavy leptons ({nu}{sub 4}) in W decays was carried out the D0 detector at the Fermilab Tevatron at {radical}{bar s} = 1.8 TeV. The {nu}{sub 4} is assumed to be produced via mixing with the first generation neutrino only. We looked for a three electron final state event topology. The data used in this analysis represent 12.2 pb{sup {minus}1} taken during the 1992--1993 run. No candidates were found. We set a preliminary limit beyond the LEP limit for the considered mixing case on the {vert_bar}U{sub e4}{vert_bar}{sup 2} {minus} m{sub {nu}4} plane.
Date: July 1, 1995
Creator: Abachi, S.; Abbott, B.; Abolins, M. & Collaboration, D0
Partner: UNT Libraries Government Documents Department

Color coherent radiation in multijet events from p{bar p} collisions at {radical}s = 1.8 TeV

Description: We report on a study of color coherence effects in p{bar p} collisions based on data collected by the D0 detector during the 1992-1993 run of the Fermilab Tevatron collider at the center of mass energy {radical}s = 1.8 TeV. We demonstrate initial-to-final state color interference effects by measuring spatial correlations between soft and hard jets in multijet events. The data are compared to Monte Carlo simulations with different color coherence implementations and to the predictions of a NLO parton level calculation.
Date: August 1, 1995
Creator: Abachi, S.; Ahn, S. & Baldin, B.
Partner: UNT Libraries Government Documents Department

A PC-based software package for modeling DOE mixed-waste management options

Description: The U.S. Department of Energy (DOE) Headquarters and associated contractors have developed an IBM PC-based software package that estimates costs, schedules, and public and occupational health risks for a range of mixed-waste management options. A key application of the software package is the comparison of various waste-treatment options documented in the draft Site Treatment Plans prepared in accordance with the requirements of the Federal Facility Compliance Act of 1992. This automated Systems Analysis Methodology consists of a user interface for configuring complexwide or site-specific waste-management options; calculational algorithms for cost, schedule and risk; and user-selected graphical or tabular output of results. The mixed-waste management activities modeled in the automated Systems Analysis Methodology include waste storage, characterization, handling, transportation, treatment, and disposal. Analyses of treatment options identified in the draft Site Treatment Plans suggest potential cost and schedule savings from consolidation of proposed treatment facilities. This paper presents an overview of the automated Systems Analysis Methodology.
Date: February 1, 1995
Creator: Abashian, M.S.; Carney, C. & Schum, K.
Partner: UNT Libraries Government Documents Department

Developing a Panelboard Trainer Using SIMVOX and PROVOX

Description: Several challenges existed in creating a system that would be valuable for training operators: the robustness and accuracy of the process model, the operator interface to the process, and the communication between the operator interface and the process models. Cost and implementation time were also important factors. Two possible implementation plans were examined. The first option was to develop a computer tool through which the operator could operate the process through interaction with the mouse and keyboard. The entire panel board system could be created in computer graphics and a process model attached. The second option was to construct a complete replica of the control room panelboard in a training environment. Operations personnel expressed a strong preference for creating the panel board replica. Concerns were expressed about the comfort level of the operators training on a computer tool, and the value of the operators becoming thoroughly familiar with the physical location of the equipment in the panelboard was believed to be high. It was therefore decided to create a replica of the control room panelboard.
Date: November 20, 1995
Creator: Abbott, L.A.
Partner: UNT Libraries Government Documents Department

A limit on {sigma} {center_dot} BR (B{sub c}{sup {+-}} {yields} J/{psi} + {pi}{sup {+-}})/{sigma} {center_dot} BR(B{sub u}{sup {+-}} {yields} J/{psi} + K{sup {+-}}) in {radical}s = 1.8 TeV proton-antiproton collisions

Description: We report on the results of a search for the B{sub c} (b{bar c}) meson in the decay B{sub c}{sup +-} {yields} J/{psi} + {pi}{sup +-}. This search is guided by a control sample of decays of B{sub u} mesons to J/{psi} + K and uses {approx_equal} 75pb{sup -1} of data collected at the Collider Detector Facility (CDF) at Fermilab. The lifetime of the B{sub c} meson is unknown, so the 95% confidence level limit on {sigma} {center_dot} BR(B{sub c} {yields} {psi} + {pi})/{sigma} {center_dot} BR(B{sub u} {yields} {psi} + K) is obtained as a function of the B{sub c} lifetime.
Date: July 15, 1995
Creator: Abe, F.
Partner: UNT Libraries Government Documents Department

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

Measurement of the mass of the B{sub s}{sup 0} meson in {bar p}p collisions at {radical}s = 1.8 TeV

Description: We measure the mass of the B{sub s}{sup 0} meson by fully reconstructing the decay B{sub s}{sup 0} {yields} J/{psi} {phi} with the subsequent decays J/{psi} {yields} {mu}{sup +} {mu}{sup {minus}} and {phi} {yields} K{sup +} K{sup {minus}}. The data was obtained from 19.3 pb{sup {minus}1} of integrated luminosity of {bar p}p collisions at {radical}s = 1.8 TeV using the Collider Detector at Fermilab (CDF). A sample of 80,000 inclusive J/{psi} {yields} {mu}{sup +}{mu}{sup {minus}} events is used to study systematic biases in track reconstruction and is used to calibrate the momentum scale. We reconstruct the kinematically similar decays B{sup {minus}} {yields} J/{psi} K{sup {minus}} and B{sup 0} {yields} J/{psi} K* to study the mass measurement technique used for the B{sup 0} meson. Based on the observation of 32 {plus_minus} 6 candidates, the mass of the B{sub s}{sup 0} meson is measured to be 5369.9 {plus_minus} 2.3 {plus_minus} 1.3 MeV/c{sup 2}.
Date: July 1995
Creator: Abe, F.
Partner: UNT Libraries Government Documents Department