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Inclusive J/{psi}, {psi} (2S) and b-quark production in {bar p}p collisions at {radical}s = 1.8 TeV

Description: Inclusive J/{psi} and {psi}(2S) production has been studied in p{bar p} collisions at {radical}s = 1.8 TeV with the Collider Detector at Fermilab. The products of production cross section times the branching fraction of J/{psi}({psi}(2S)) to {mu}{sup +}{mu}{sup {minus}} are reported as functions of the J/{psi}({psi}(2S)) P{sub T} in the kinematic range P{sub T} > 6 GeV/c and {vert_bar}{eta}{vert_bar} {le} 0.5. The products of the integrated cross section times branching fraction and the b-quark production cross section calculated from these values are also reported.
Date: November 1, 1992
Creator: Papadimitriou, V. & Collaboration, CDF
Partner: UNT Libraries Government Documents Department

Inclusive J/{psi}, {psi}(2S) and b-quark production in {bar p}p collisions at {radical}s = 1.8 TeV

Description: Inclusive J/{psi} and {psi}(2S) production has been studied in {bar p}p collisions at {radical}s = 1.8 TeV using the Collider Detector at Fermilab. The products of production cross section times branching fraction have been measured as functions of P{sub T} for J/{psi}({psi}(2S)) {yields} {mu}{sup +}{mu}{sup {minus}} in the kinematic range P{sub T}{sup J/{psi}({psi}(2S))} > 6 GeV/c and {vert_bar}{eta}{sup J/{psi}({psi}(2S)){vert_bar}} {le} 0.5. The products of the integrated cross section times branching fraction are calculated and used to obtain an inclusive b-quark production cross section.
Date: November 1, 1992
Creator: Fuess, T. A. & Collaboration), (CDF
Partner: UNT Libraries Government Documents Department

Inclusive {chi}{sub c} production in {bar p}p collisions at {radical}s = 1.8 TeV

Description: We report the full reconstruction of X, mesons through the decay chain {chi}{sub c} {yields} J/{psi}{gamma}, J/{psi} {yields} {mu}{sup +}{mu}{sup {minus}}, using data obtained at the Collider Detector at Fermilab in {bar p}p collisions at {radical}s = 1.8 TeV. This sample, the first observed at a hadron collider, is then used to measure the {chi}{sub s} meson production cross section times branching fractions. We obtain {sigma} {center_dot} Br = 3.2 {plus_minus} 0.4(stat) {plus_minus} 1.1(syst) nb for {chi}{sub s}, mesons with P{sub T} > T.0 GeV/c{sup 2} and pseudorapidity {vert_bar}{eta}{vert_bar} < 0.5. From this and the inclusive J/ {psi} cross section we calculate the inclusive b-quark crow section.
Date: November 1, 1992
Creator: Boswell, C. M. & Collaboration), (CDF
Partner: UNT Libraries Government Documents Department

SVX b physics prospects

Description: CDF has enhanced its capabilities for b-physics with the installation of a silicon vertex detector (SVX), which provides precise 2-dimensional tracking. The SVX impact parameter (IP) resolution ({approximately} 13{mu}m for P{sub t} {gt} 10 GeV) is well suited to detecting displaced secondary vertices (SV) from b-hadron decays (c{tau}{sub B} {approx_equal} 390{mu}m). In this paper we show evidence of SV detection using the {Psi} {yields} {mu}{sup {plus}} {mu}{sup {minus}} sample, which is b-enriched, and describe some prospects of b physics opened by the SVX with 25 pb{sup {minus}1}, the goal integrated luminosity of present run.
Date: November 1, 1992
Creator: Dell`Agnello, S. & Collaboration, The CDF
Partner: UNT Libraries Government Documents Department

Novel spin effects in quantum chromodynamics

Description: This report discusses a number of interesting hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. These include constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton; the principle of hadron helicity retention in high x{sub F} inclusive reactions; predictions based on total hadron helicity conservation in high momentum transfer exclusive reactions; the dependence of nuclear structure functions and shadowing on virtual photon polarization; and general constraints on the magnetic moment of hadrons. I also will discuss the implications of several measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}.
Date: February 1, 1993
Creator: Brodsky, S. J.
Partner: UNT Libraries Government Documents Department

Dynamical models of B yields. psi. /J K sub + *

Description: An issue of some interest in the general theory of CP violation on B meson decay is the relative admixture of even and odd final CP eigenstates in B {yields} {psi}/JK*{sub +}. For example, dominance of one sign of CP in this decay would increase the available modes for measuring the CP violation in the respective B meson decays in a beauty factory by a factor {approximately}2.5 and, hence, would decrease the luminosity requirements for such a factory from the CP violation perspective. Here, we therefore study this relative admixture in several dynamical models of the respective decay. We are encouraged by our findings. 12 refs., 3 figs.
Date: September 1, 1990
Creator: Ward, B.F.L. (Tennessee Univ., Knoxville, TN (USA). Dept. of Physics and Astronomy Stanford Linear Accelerator Center, Menlo Park, CA (USA) International Centre for Theoretical Physics, Trieste (Italy))
Partner: UNT Libraries Government Documents Department

Tests of QCD at HERA: determination of the gluon density

Description: An overview is given of the various methods available to the colliding beam experiments at HERA to determine the gluon density of the proton. The article includes a description of fits to the structure function F{sub 2}, of studies of dijet and open charm production in deep inelastic scattering, of elastic and inelastic {psi} photoproduction, and of inclusive diffractive scattering. 13 refs., 8 figs.
Date: December 31, 1996
Creator: Repond, J.
Partner: UNT Libraries Government Documents Department

Quarkonia production at CDF

Description: We present the results of J/{psi}, {psi}{prime}, {chi}{sub c} and {Upsilon}(1S), {Upsilon}(2S), {Upsilon}(3S) production in the proton-antiproton collisions at {radical}s = 1800 GeV measured with the CDF Detector. Contributions of different production mechanisms are discussed. 10 refs., 7 figs.
Date: August 1, 1996
Creator: Demina, R.
Partner: UNT Libraries Government Documents Department

B physics with the CDF Run II upgrade

Description: During the Run 1 data taking period, from 1992 through 1995, CDF has acquired 110 pb{sup {minus}1} of p{anti p} collisions at a center of mass energy of 1,800 GeV. This data has provided many results on B physics, and provides a basis for extrapolating to Run 2, which is scheduled to start in 1999 after major upgrades to both the accelerator and detector. The authors present herein a summary of Run 1 results relevant to an analysis of the CP asymmetry in B {yields} J/{psi}K{sub s}, the CDF upgrade plans for Run 2, and some of the main B physics goals related to the exploration of the origin of CP violation.
Date: January 1, 1996
Creator: DeJongh, F.
Partner: UNT Libraries Government Documents Department

Experimental studies of elementary particle interactions at high energies. Summary technical progress report

Description: This is a report of the research activities of the Experimental High Energy Physics group of The Rockefeller University. As this is an annual progress report, the emphasis is on last year`s research activities. However, since it is the last of a series of 5 such reports to be submitted to the DOE under the present 5 year contract, an effort has been made to provide comprehensive coverage of the research activities of the group throughout the contract period. In the past 5 years, the research program encompassed three major areas: the UA-6 experiment at CERN, the CDF experiment at Fermilab, and several SSC projects. The UA-6 experiment studies direct-{gamma} and J/{Psi} production in pp and {bar p}p interactions at {radical}s = 22.5 GeV.4. In the CDFF experiment the authors have concentrated in the area of small angle physics, where the objective has been to measure the elastic, diffractive and total cross sections, and to provide an absolute calibration of the machine luminosity. The SSC research projects related to two experiments: The Solenoidal Detector Collaboration and the ``low p{sub T} physics`` experiment.
Date: March 31, 1992
Partner: UNT Libraries Government Documents Department

Support of experimental high energy physics research at the University of South Carolina. Final technical report, 1980--1992

Description: Twelve years of support by the US Department of Energy have turned a two man team with no equipment and no graduate students working on a single experiment into an active group of four professors, one post-doctoral research associate and three graduate students working with appropriate equipment on three major experiments and several other projects. 162 references.
Date: December 31, 1992
Creator: Childers, R.L.; Darden, C.W.; Rosenfeld, C. & Wilson, J.R.
Partner: UNT Libraries Government Documents Department

Experimental possibilities for observation of CP violation in B decay

Description: The detection and the measurement of CP violation in the decays of B hadrons will require the accumulation of large numbers of B decays in particular exclusive modes. The potential of beauty hadroproduction experiments for obtaining these large data samples is examined in the context of various trigger and analysis strategies. The possibilities for doing such experiments at present hadron machines is compared with the potential for such experiments at the SSC. 3 refs., 3 figs., 4 tabs.
Date: February 1, 1988
Creator: Cox, B.
Partner: UNT Libraries Government Documents Department

J/. psi. and. Upsilon. production at CDF

Description: Characteristics of J/{psi} and {Upsilon} produced at the Tevatron and detected in the dimuon channel at CDF are reviewed. The masses of the J/{psi} and {Upsilon} are measured to be 3.096 {plus minus} 0.001 GeV/c{sup 2} and 9.469 {plus minus} 0.010 GeV/c{sup 2} respectively. These mass measurements are used to determine the systematic uncertainty on the momentum scale in the central tracking chamber. 2 refs., 14 figs.
Date: January 1, 1990
Creator: Liss, T. (Illinois Univ., Urbana, IL (USA))
Partner: UNT Libraries Government Documents Department

Heavy flavor production in fixed-target experiments

Description: This presentation is a review of recent measurements on charm production at fixed-target experiments. The measurements are relevant to a number of basic physics issues: tests of perturbative QCD, fragmentation, and basic hadronic structure. We now have high quality, high statistics data from several fixed-target experiments. These include a total of about 30,000 fully reconstructed open charm decays and even more copious J/{Psi}, {Psi}, and {Upsilon} decays. Reconstruction of the full data is now reaching completion and we await final results for systematic physics interpretations. This review of the current situation will be followed by a brief look beyond, toward beauty production at fixed-target experiments.
Date: September 1, 1990
Creator: Appel, J.A.
Partner: UNT Libraries Government Documents Department

Status report on Fermilab experiment E-760: A study of charmonium produced by proton-antiproton annihilation

Description: This was a status report on Fermilab experiment E-760 -- an experiment to study charmonium states by resonant formation in proton-antiproton annihilation. The experiment uses antiprotons circulating in the Fermilab antiproton-accumulator as the beam and an internal hydrogen gas-jet as the target. Data taking with the full complement of apparatus started in early July 1990.
Date: September 4, 1990
Creator: Pordes, S.
Partner: UNT Libraries Government Documents Department

The production of J//psi/ and associated particles in the collision of 530 GeV/c protons and pions with nuclear targets

Description: We have studied the production of the J//psi/ and associated particles using the E672/E706 spectrometer at Fermilab. Preliminary results are presented from the first run in 1987--1988 with 530 GeV/c p//pi//sup +/ and /pi//sup /minus// beams on a variety of nuclear targets. The A-dependance of J//psi/ production with /pi//sup /minus// beam was found to agree with an A/sup /alpha// parametrization with /alpha/ = 0.85 /plus minus/ 0.06 for X/sub F/ > 0.1. We have found that (41 /plus minus/ 22)% of the J//psi/'s produced in the p//pi//sup +/ beam are consistent with the radiative decay /chi/ /yields/J//psi/+/gamma/. The future analysis goals of the experiment are also discussed. 10 refs., 9 figs.
Date: January 1, 1989
Creator: De, K.; Crittenden, R.; Dzierba, A.; Kartik, S.; Li, R.; Markham, S. et al.
Partner: UNT Libraries Government Documents Department

Search for the. Lambda. sub b baryon at CDF

Description: The {Lambda}{sub b} baryon has been observed recently by UA1 through its decay {Lambda}{sub b} {yields} J/{psi}{Lambda}{degrees}. Although CDF finds twice as many J/{psi} and observes {Lambda}{degrees} decays, no evidence for an {Lambda}{sub b} signal is seen. The UA1 data supports a lower than expected production P{sub T} for the {Lambda}{sub b}, and therefore, a lower pion P{sub T}, below the observation threshold of CDF. This result suggests that UA1 and CDF are probably not inconsistent, but also that the production models are not quite right.
Date: April 1, 1992
Creator: Gauthier, A. (Illinois Univ., Urbana, IL (United States))
Partner: UNT Libraries Government Documents Department

B-physics at CDF

Description: During the 1988/1989 run at the Fermilab Tevatron, the CDF detector collected {approx equal}4.1 pb{sup {minus}1} of p{bar p} data at {radical}s = 1.8 TeV. The main goals of this run being physics at high p{sub t}, the CDF trigger was tuned'' for maximizing signals from Z{sup 0}s, Ws, t-quarks, etc. As such, compared to the high p{sub t} physics, the b-physics program was of secondary importance other than that which would be used for background calculations. Also, CDF had no vertex chamber capability for seeing displaced vertices. However, significant b-quark, physics results are evident in two data samples; inclusive electrons and inclusive J/{psi} where J/{psi} {yields} {mu}{sup +}{mu}{sup {minus}}. We can then ask ourselves, given all this, why is it that CDF is able to do b-quark physics The answer is that nature has been kind enough to provide b-quarks at an extremely high rate at the Tevatron. The production cross-section for b{bar b} production is quite large. In the rest of this paper, I will try to specify the goals for b-physics using the inclusive electrons and J/{psi} signals for the 1988/1989 data set. I will then provide a brief look at the data, and will finish with some highly speculative guesses as to whether or not experiments at the Tevatron which look for CP violation in the b sector are possible.
Date: December 10, 1990
Creator: Baden, A.R. (Harvard Univ., Cambridge, MA (USA))
Partner: UNT Libraries Government Documents Department

Amplitude analysis of the K anti K system in J/. psi. radiative decay

Description: Preliminary results of a mass independent amplitude analysis of J/{psi} radiative decays into K {bar K} final states are presented. A large component of spin zero is observed at the f{sub 2}/{theta}(1720) mass region; however, a small spin two component at this mass region cannot be excluded with the present statistics. 9 refs., 7 figs.
Date: November 1, 1990
Creator: Chen, Liang-Ping (Vanderbilt Univ., Nashville, TN (USA). Dept. of Physics and Astronomy)
Partner: UNT Libraries Government Documents Department

A study of the. alpha. sub 0 (980) meson in radiative J/. psi. decays

Description: Using the decay sequence J/{psi} {yields} {gamma}X,X {yields} a{sub 0}{sup {plus minus}}(980){pi}{sup {minus plus}}, a{sub 0}{sup {plus minus}}(980) {yields} {eta}{pi}{sup {plus minus}}, where X is the f{sub 1}(1285) or {eta}(1400), the {eta}{pi}{sup +} vs {eta}{pi}{sup {minus}} Dalitz plot intensity distributions are fitted with a model containing a coupled-channel parametrization of the a{sub 0}(980). Preliminary values for the spin of X, the mass and width of the a{sub 0}{sup {plus minus}}(980) to {eta}{pi}{sup {plus minus}}, and the ratio of a{sub 0}{sup +}(980) coupling strengths, g{sub K}{sup 2}/g{sub {eta}}{sup 2}, to {bar K}{sup 0}K{sup +} and {eta}{pi}{sup +} are determined. From this model, the predictions for the ratios of branching ratios r{sub X} = B(X {yields} a{sub 0}(980){pi}){center dot}B(a{sub 0}(980) {yields} K{bar K})/B(X {yields} a{sub 0}{sup {plus minus}}(980){pi}){center dot}B(a{sub 0}{sup {plus minus}}(980) {yields} {eta}{pi}{sup {plus minus}}) are compared with those obtained from MARK III Partial Waves analyses of the decays J/{psi} {yields} {gamma}K{sub s}{sup 0}K{sup {plus minus}}{pi}{sup {minus plus}} and J/{psi} {yields} {gamma}{eta}{pi}{sup +}{pi}{sup {minus}}. 12 refs., 3 figs., 4 tabs.
Date: December 1, 1990
Creator: Lockman, W.S. (California Univ., Santa Cruz, CA (USA). Inst. for Particle Physics)
Partner: UNT Libraries Government Documents Department

J/. psi. suppression: Catching up with the comovers

Description: The combined role of inelastic scattering with nucleons and comoving secondary particles in J/{psi} suppression is explored. An analysis of the latest FNAL and CERN data suggests that the high-density comover contribution emerges with increasing incident energy and A.
Date: August 27, 1990
Creator: Vogt, R. (Lawrence Livermore National Lab., CA (USA) Lawrence Berkeley Lab., CA (USA)) & Gavin, S. (Helsinki Univ. (Finland). Research Inst. for Theoretical Physics)
Partner: UNT Libraries Government Documents Department

Nuclear medium effects on quarks, gluons, and on vector meson production: New insights from dimuon production

Description: A precise measurement of the atomic mass dependence of dimuon continuum and vector-meson production induced by 800 GeV/c protons is reported. Approximately 700,000 muon pairs with dimuon mass M {ge} 3 GeV were recorded from targets of {sup 2}H, C, Ca, Fe, and W. The ratio of Drell-Yan dimuon yield per nucleon for nuclei versus {sup 2}H, R = Y{sub A}/Y{sub 2H}, is sensitive to modifications of the antiquark sea in nuclei. No nuclear dependence of this ratio is observed over the range of target-quark momentum fraction 0.1 < x{sub t} < 0.3. For x{sub t} < 0.1 the ratio is slightly less than unity for the heavy nuclei. These results are compared with predictions of models of the EMC effect. A depletion of the yield per nucleon from heavy nuclei is observed for the J{Psi}, {Psi}{prime}, and {Upsilon} production. This depletion exhibits strong dependence on x{sub f} and p{sub t}. 25 refs., 19 figs., 1 tab.
Date: January 1, 1990
Creator: Leitch, M.J.; Alde, D.M.; Baer, H.W.; Carey, T.A.; Garvey, G.T.; Klein, A. et al.
Partner: UNT Libraries Government Documents Department

Quark Matter '87: Concluding remarks

Description: This year marked the beginning of the experimental program at BNL and CERN to probe the properties of ultra dense hadronic matter and to search for the quark-gluon plasma phase of matter. Possible implications of the preliminary findings are discussed. Problems needing further theoretical and experimental study are pointed out. 50 refs.
Date: March 1, 1988
Creator: Gyulassy, M.
Partner: UNT Libraries Government Documents Department