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J/{psi} and {psi}{prime} production at CDF

Description: This paper presents measurements of the J/{psi} and {psi}{prime} production cross sections in p{ovr p} collisions at {radical}s = 1.8 TeV. The cross sections are measured in the kinematic region P{sub T} {gt} 5 GeV/c, {vert_bar}{eta}{vert_bar} {lt} 0.6 using the dimuon decay channel. The fraction of events from B decays is measured and used to calculate the J/{psi} and {psi}{prime} cross sections from B decay. The fraction of J/{psi} events from {chi}{sub c} decays is also measured and used to calculate the J/{psi} cross section from direct production. 11 refs., 5 figs., 1 tab.
Date: July 1, 1996
Creator: Abe, F.
Partner: UNT Libraries Government Documents Department

Comparison of the total cross sections measurements of CDF and E811

Description: The total cross section at {radical}s = 1.8 TeV has been measured by three groups (CDF, E710, and E811). We think that CDF should quote results based only on our own measurement. We also indicate how to compare cross sections measured by both CDF and D0.
Date: March 3, 1999
Creator: Albrow, M.; Beretvas, A.; Nodulman, L. & Giromini, P.
Partner: UNT Libraries Government Documents Department

{Lambda}{sub b} results from CDF

Description: The CDF experiment has recorded 110 pb{sup {minus}1} of p{ovr p} collisions at {radical}s = 1.8 TeV during the 1992-1995 data taking period. Using this dataset, searches for inclusive and semileptonic {Lambda}{sub b} decays were performed. The {Lambda}{sub b} mass was measured to be M{sub {Lambda}{sub b}} {equals} 5623 {plus_minus} 5(stat.) {plus_minus} 4(syst.) MeV/c{sup 2}, using a sample of exclusively reconstructed {Lambda}{sub b} candidate events in the {Lambda}{sub b} {r_arrow} {Lambda}J/{psi} channel. The {Lambda}{sub b} lifetime was measured to be {tau}{sub {Lambda}{sub b}} {equals} 1. 32 {plus_minus} 0.08(stat.) {plus_minus} 0.05(syst.) ps, using a sample of 197 {plus_minus} 25 partially reconstructed semileptonic {Lambda}{sub b} {r_arrow} l{sup {minus}}{Lambda}{sub c}{sup {plus}}X decays, with {Lambda}{sub c}{sup {plus}} reconstructed from its decay to the pK{sup {minus}}{pi}{sup {plus}} final state. Using the same decay channels, the product branching ratios were measured to be f(b {r_arrow} {Lambda}{sub b})B({Lambda}{sub b} {r_arrow} {Lambda}J/{psi}) = 4.2{plus_minus}1.8(stat.){plus_minus}0.7(syst. ){times}10{sup {minus}5} and f(b {r_arrow} {Lambda}{sub b})B({Lambda}{sub b} {r_arrow} l{sup {minus}}{Lambda}{sub c}{sup {plus}}{ovr {nu}})B({Lambda}{sub c}{sup {plus}} {r_arrow} pK{sup {minus}}{pi}{sup {plus}}) {equals} 9.3{plus_minus}2.5(stat. ){plus_minus}{sup {plus}4.6}{sub {minus}4.0}(syst.){times}10{sup {minus}4}, where f(b {r_arrow} {Lambda}{sub b}) is the fraction of b quarks forming b baryons, and l is either an electron or a muon. 15 refs., 4 figs., 1 tab.
Date: September 1, 1996
Creator: Tkaczyk, S.
Partner: UNT Libraries Government Documents Department

Search for new exotic particles at CDF

Description: We present recent results of searches for new particles beyond the Standard Model at the Collider Detector at Fermilab (CDF). These include searches for heavy gauge bosons (Z{prime}, W{prime}), leptoquarks and stable massive charged particles. For most of these particles we set the currently most stringent limits. 15 refs., 7 figs.
Date: July 1, 1996
Creator: Wensel, H.
Partner: UNT Libraries Government Documents Department

Preliminary measurement of the inclusive jet and dijet cross section in {bar p}p collisions at {radical} s = 1.8 TeV

Description: We report on preliminary measurements of the central, |{eta}| {le} 0.5, inclusive jet and dijet cross sections at {radical}s = 1.8 TeV. Two data sets with integrated luminosities of 91 pb{sup {minus}1} and 14 pb{sup {minus}1} were collected at the Fermilab Tevatron p{ovr p} Collider with the D0 detector. The inclusive jet cross section measured with both data sets and reported as a function of transverse jet energy (35 GeV {le} E{sub T} {le} 470 GeV) and the dijet cross section measured with the 91 pb{sup {minus}1} data set and reported as a function of dijet mass (200 GeV {le} M{sub JJ} {le} 1 TeV) are in excellent agreement with next-to-leading order QCD. 11 refs., 5 figs.
Date: June 1, 1996
Creator: Blazey, G.C.
Partner: UNT Libraries Government Documents Department

Electroweak measurements from CDF and D0

Description: This paper highlights results from electroweak measurements recently obtained by the CDF and D0 collaborations in 1.8 TeV p{ovr p} collisions. The W decay width was extracted from the measurement of W/Z cross section times leptonic branching ratios, and in a direct measurement from a fit of the high-mass tail of the transverse mass spectrum of the W system. Various limits on anomalous gauge boson couplings were obtained in studies of W/Z + {gamma} processes, single leptonic WW, WZ production and double leptonic WW production. Values for {sigma}B(W{gamma}{r_arrow}l{nu}{gamma}), {sigma}B(Z{gamma}{r_arrow}l{sup +}l{sup -}{gamma}), and {sigma}(p{ovr p}{r_arrow}WW + X) were measured. CDF also reports on the observation of an asymmetry in photon rapidity distributions as predicted by the Standard Model. 17 refs., 2 figs., 1 tab.
Date: July 1, 1996
Creator: Neuberger, D. & Collaborations, CDF and D0
Partner: UNT Libraries Government Documents Department

Search for a fourth generation charge {minus}1/3 quark via flavor changing neutral currents

Description: There is some likelihood that a light (< m{sub t}) fourth generation charge -1/3 quark (b{prime}) would decay predominantly via loop induced flavor changing neutral currents. The charged current decay of b{prime} to charm would be highly Cabibbo suppressed due to the fact that it changes the generation number by two. The D0 experiment has searched for b{prime} pair production where one or both b{prime} quarks decays via b{prime} {r_arrow} b+{gamma}, giving signatures photon + three jets and two photons + two jets. WE don not see a significant excess of such events over background. In both modes, we set an upper limit on the cross section times branching ratio that is sufficient to rule out a standard sequential b{prime} decaying predominantly via FCNC in the mass range m{sub Z}/2 < m{sub b{prime}} < m{sub Z} + m{sub b}. For b{prime} masses larger than this, the dominant FCNC decay mode is expected to be b{prime} {r_arrow} b + Z. 14 refs., 13 figs., 5 tabs.
Date: July 1, 1996
Creator: D0 Collaboration
Partner: UNT Libraries Government Documents Department

Measurement of the t {anti t} cross section at D0

Description: We have measured the t{anti t} cross-section in p{anti p} collisions at {radical}s = 1.8 TeV using dilepton and single lepton final states. This analysis uses approximately 106 pb{sup -1} of data collected with the D0 detector at Fermilab during the 1992-1996 run. We observe 37 events with an expected background of 13.4 {+-} 3.4 events, giving {sigma}{sub t{anti t}} of 5.3 {+-} 1.8 pb for m{sub t} = 169 GeV. 4 refs., 1 fig., 1 tab.
Date: August 1, 1996
Creator: Kehoe, R.L.
Partner: UNT Libraries Government Documents Department

Polarized and unpolarized double prommpt photon production in next-to-leading order QCD

Description: We calculate O({alpha}{sub s}) corrections to inclusive and isolated double prompt photon production, both for the unpolarized case, and for longitudinal polarization of the incoming hadrons. The calculation is performed using purely analytical techniques for the inclusive case, and a combination of analytical and Monte Carlo techniques to perform the phase space integration in the isolated case. A brief phenomenological study is made of the process pp {r_arrow} {gamma}{gamma}X at CMS energies appropriate for the RHIC heavy ion collider. 21 refs., 8 figs.
Date: March 1, 1996
Creator: Coriano, C. & Gordon, L.E.
Partner: UNT Libraries Government Documents Department

Heavy quark results at D0

Description: Recent results in heavy quark physics from the D0 experiment at the Fermilab Tevatron Collider are reported. Topics included are top quark production and mass determination, bottom production and correlations, and charmonium production. 20 refs., 10 figs., 2 tabs.
Date: January 1, 1997
Creator: Fein, D.K.
Partner: UNT Libraries Government Documents Department

W and Z boson production with jets and inclusive jet production in p pbar collisions at square root s = 1.8TeV

Description: The production properties of jets produced in p{ovr p} collisions at {radical}s = 1.8 TeV have been measured using the CDF detector. The data are compared to predictions of leading order and next to leading order QCD predictions. Both inclusive jets and those produced in association with W and Z bosons are used for this analysis. In general, good agreement with QCD predictions is found except for very high E{sub t} inclusive jets. 10 refs., 7 figs., 2 tabs.
Date: August 1, 1996
Creator: Goshaw, A.T.
Partner: UNT Libraries Government Documents Department

The dijet mass spectrum with the D0 detector

Description: The authors present preliminary results from an analysis of dijet data collected during the 1994--1995 Tevatron Collider run with an integrated luminosity of 91 pb{sup {minus}1}. Measurements of dijet mass spectrum distributions in {anti p}p collisions at {radical}s = 1.8 TeV are compared with next-to-leading order QCD theory.
Date: September 1, 1996
Creator: Choi, S.
Partner: UNT Libraries Government Documents Department

Bose-Einstein correlation of positive kaon pairs in E859--Extended results and model comparisons

Description: Results are presented for multidimensional Bose-Einstein Correlation analyses of {pi}{sup +} and K{sup +} mid-rapidity pairs collected by BNL-AGS experiment E859 in 14.6 A{center_dot}GeV/c Si + Au central collisions. Comparisons are made to the cascade codes ARC (v. 1.9.5) and RQMD (v. 1.08). 14 refs., 2 figs., 3 tabs.
Date: December 31, 1995
Creator: Cianciolo, V.
Partner: UNT Libraries Government Documents Department

Measurement of the lifetime of the B{sup o}{sub s} meson from D{sup minus}{sub s}{ell}{sup plus} correlations

Description: The lifetime of the B{sub s}{sup 0} meson is measured using the semileptonic decay B{sub s}{sup 0} {r_arrow} D{sub s}{sup {minus}}l{sup {plus}}{nu}X. The data sample consists of approximately 110 pb{sup {minus}1} of p{ovr p} collisions at {radical}s = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider. There are 254{plus_minus}21 D{sub s}{sup {minus}}l{sup {plus}} signal events where the D{sub s}{sup {plus}} is reconstructed through its decay mode D{sub s}{sup {minus}} {r_arrow} {phi}{pi}{sup {minus}}, {phi} {r_arrow} K{sup {plus}}K{sup {minus}}. Using these events, the B{sub s}{sup 0} meson lifetime is determined to be {tau}(B{sub s}{sup 0}) {equals} 1.37{sup {plus}0.14}{sub {minus}0.12}(stat.){plus_minus}0.04(syst.) ps. The B{sub s}{sup 0} meson proper decay length distribution has been examined for a lifetime difference between the two CP eigenstates of the B{sub s}{sup 0} meson, B{sub s}{sup H} and B{sub s}{sup L}. 12 refs., 3 figs., 1 tab.
Date: July 1996
Creator: Burkett, K. & Paulini, M.
Partner: UNT Libraries Government Documents Department

Recent QCD results from the Tevatron

Description: Recent QCD results from the CDF and D0 detectors at the Tevatron proton-antiproton collider are presented. An outlook for future QCD tests at the Tevatron collider is also breifly discussed. 27 refs., 11 figs.
Date: February 1, 1997
Creator: Pickarz, Henryk
Partner: UNT Libraries Government Documents Department

Top mass measurement at CDF

Description: We present the measurement of the top quark mass using L = 110 pb{sup -1} data sample of p{ovr p} collisions at {radical}s = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). We show the results for the different channels and discuss with some emphasis the determination of the systematic uncertainties. 7 refs., 10 figs., 5 tabs.
Date: June 1, 1996
Creator: Rolli, S.
Partner: UNT Libraries Government Documents Department

Searches for new particles at D0

Description: We report the results of searches at the Tevatron for first and second generation leptoquarks and for new charged gauge bosons. The data were collected with the D0 detector from {ital p{anti p}} collisions at {radical}s=1.8 TeV. No evidence for the existence of these particles is seen and mass limits are set. We report new preliminary results of a search for a heavy neutral gauge boson in the process Z{prime}{r_arrow}{ital ee}, from an integrated luminosity of 105 pb{sup -1}. We exclude the existence of a Z{prime} of mass less than 670 GeV/c{sup 2}, assuming a Z{prime} with the same coupling strengths to quarks and leptons as the standard model Z boson. 13 refs., 5 figs., 1 tab.
Date: September 1, 1996
Creator: Eppley, G.W.
Partner: UNT Libraries Government Documents Department

Electroweak radiative corrections to W boson production at the Tevatron

Description: We present some results of a new calculation of the O({alpha}) electroweak radiative corrections to W boson production at hadron colliders with special emphasis on the transverse mass distribution.
Date: November 14, 1996
Creator: Baur, U. & Keller, S., Wackeroth, D.
Partner: UNT Libraries Government Documents Department

Branching fractions of B{sup plus} {r_arrow} {Psi}(2S)K{sup plus} and B{sup O} {r_arrow} {Psi}(2S)K{sup {asterisk}0} decays at CDF

Description: This paper describes the observation of the decays B{sup {plus}} {r_arrow} {psi}(2S)K{sup {plus}} and B{sup 0} {r_arrow} {psi}(2S)K{sup {asterisk}}(892){sup 0} in 1.8 TeV p{ovr p} collisions and presents measurements of the branching fractions Br(B{sup {plus}} {r_arrow} {psi}(2S)K{sup {plus}}) and Br(B{sup 0} {r_arrow} {psi}(2S)K{sup {asterisk}}(892){sup 0}) relative to Br(B{sup {plus}} {r_arrow} J/{psi}K{sup {plus}}) and Br(B{sup 0} {r_arrow} J/{psi}K{sup {asterisk}}(892){sup 0}), respectively. The {psi}(2S) mesons are reconstructed in both the {psi}(2S) {r_arrow} {mu}{sup {plus}}{mu}{sup {minus}} and {psi}(2S) {r_arrow} J/{psi}{pi}{sup {plus}}{pi}{sup {minus}} channels. The world average branching fractions for the J/{psi} channels are used to extract the absolute branching fractions Br(B{sup {plus}} {r_arrow} {psi}(2S)K{sup {plus}}) = (6.8{plus_minus}1.0(stat.){plus_minus}1.4(syst.)){times}10{sup {minus}4} and Br(B{sup 0} {r_arrow} {psi}(2S)K{sup {asterisk}}(892){sup 0}) = (9.0{plus_minus}2.1(stat.){plus_minus}2. 0(syst.)){times}10{sup {minus}4}. 9 refs., 13 figs., 8 tabs.
Date: July 1, 1996
Creator: Warburton, A.
Partner: UNT Libraries Government Documents Department

Observation of t quark production at CDF

Description: We present CDF results on the observation of the top quark and the study of its properties using 100 pb{sup -1} of data collected at the Tevatron collider at {radical}s = 1.8 TeV during the 1992-1995 period. Updated counting results and consistency checks between these data and earlier published mass and cross section are given. 8 refs., 9 figs., 2 tabs.
Date: April 1, 1997
Creator: Yao, Weiming
Partner: UNT Libraries Government Documents Department

The inclusive jet cross section in {bar p}p collisions at {radical}s = 1.8 TeV

Description: We report on the preliminary measurement of the inclusive jet cross section for {vert_bar}{eta}{vert_bar} {le} 0.5 at {radical}s = 1.8 TeV. Two data sets with integrated luminosities of 91 pb{sup {minus}1} and 14 pb{sup {minus}1} were collected at the Fermilab Tevatron {ovr p}p Collider with the D0 detector. The inclusive jet cross sections are measured and reported as a function of transverse jet energy (35 GeV {le} E{sub T} {le} 470 GeV) are in excellent agreement with next-to-leading order QCD. 11 refs., 4 figs.
Date: July 1, 1996
Creator: Bertram, I. A.
Partner: UNT Libraries Government Documents Department

Electromagnetic dissociation of Au targets by Au beams in E862

Description: E862 is an experiment to measure Electromagnetic Dissociation (ED) of Au and Co targets by 9.89 GeV/nucleon beams from the AGS. ED occurs at impact parameters large enough so that no strong interaction occurs, but virtual photons are exchanged, resulting in the excitation of a giant resonance. The authors report the first observation of an ED cross section {sigma}{sub ED} larger than the total hadronic cross section for Au+Au of 6.1 barns. Results are given for both the single- and double-neutron removal processes and compared to calculations using both semiclassical and quantum methods, including effects from both E1 and E2 giant resonances. Predictions are extended to RHIC and LHC collider energies where ED will be a significant determinant of the quality of the stored beams.
Date: September 1, 1997
Creator: Hill, J.C.; Ewell, L.A. & Libby, B.
Partner: UNT Libraries Government Documents Department

Pion and kaon correlations in high energy heavy-ion collisions

Description: Data analysis is in progress for recent experiments performed by the NA44 collaboration with the first running of 160 A GeV {sup 208}Pb-induced reactions at the CERN SPS. Identified singles spectra were taken for pions, kaons, protons, deuterons, antiprotons and antideuterons. Two-pion interferometry measurements were made for semi-central-triggered {sup 208}Pb + Pb collisions. An upgraded multi-particle spectrometer allows high statistics data sets of identified particles to be collected near mid-rapidity. A second series of experiments will be performed in the fall of 1995 with more emphasis on identical kaon interferometry and on the measurement of rare particle spectra and correlations. Modest instrumentation upgrades by TAMU are designed to increase the trigger function for better impact parameter selection and improved collection efficiency of valid events. An effort to achieve the highest degree of projectile-target stopping is outlined and it is argued that an excitation function on the SPS is needed to better understand reaction mechanisms. Analysis of experimental results is in the final stages at LBL in the EOS collaboration for two-pion interferometry in the 1.2 A GeV Au+Au reaction, taken with full event characterization. 35 refs., 15 figs., 5 tabs.
Date: December 31, 1996
Creator: Wolf, K.L. & Wolf, K.L.
Partner: UNT Libraries Government Documents Department