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Inclusive production of vector mesons in e/sup +/e/sup minus/ annihilation at. sqrt. s = 29 GeV

Description: This thesis describes the measurement of multiplicities and differential cross-sections of the /rho//sup 0/, K*/sup 0/, and /phi/ in e/sup +/e/sup -/ annihilation at ..sqrt..s = 29 GeV, using data collected by the TPC/2..gamma.. Detector Facility at PEP. The number of vector mesons per event is determined to be N(/rho//sup 0/) = 0.77 +- 0.08 +- 0.15, N(K*/sup 0/ + /bar K/*/sup 0/) = 0.58 +- 0.05 +- 0.11, and N(/phi/) = 0.076 +- 0.010 +- 0.012. These multiplicities are used to find that the ratio of strange quarks to up quarks produced in the hadronization process is 0.30 +- 0.07, and that the ratio of light vector mesons to all light mesons produced in the hadronization process is 0.45 +- 0.08. All results agree with previous measurements. Measurements are compared with predictions of the Lund and Webber hadronization models, neither model is particularly favored nor disfavored. 60 refs., 32 figs., 24 tabs.
Date: August 1, 1988
Creator: Edberg, T. K.
Partner: UNT Libraries Government Documents Department

Recent results on top, bottom and exotic physics at the Tevatron

Description: A summary of results from the recently concluded 1991--1993 Tevatron run is presented. Selected topics from b physics and exotic particle searches from the CDF and D0 collaborations are reviewed. Preliminary results from the CDF top search, using 12pb{sup {minus}1} from the 1992--1993 run, are given. In particular, the lepton + b-tag and dilepton analyses are discussed. Preliminary results from the CDF dilepton analysis places a lower limit on the top quark mass of 108GeV/c{sup 2} at the 95% C.L.
Date: August 1, 1993
Creator: Shaw, N. M.
Partner: UNT Libraries Government Documents Department

Signal and background in NLO QCD for the search of the intermediate mass Higgs boson at the SSC

Description: The signal and background for the search of the Standard Model Higgs boson in the intermediate mass range 80 GeV < m{sub H} < 2M{sub Z} is studied based on calculations of the cross sections in next-to-leading order QCD perturbation theory for the production of the Higgs boson via gluon-gluon fusion and for the hadronic two-photon production. The method of Monte-Carlo integration allows the application of realistic cuts (p{sub T}, rapidity, photon isolation) to the cross section. Results are given for the K-factors of the signal and the background. It turns out that the NLO corrections improve the situation for a Higgs boson mass in the range of 80--120 GeV. Furthermore, the influence of a cut on the transverse momentum of the additional jet produced in the processes gg {yields} Hg, gq {yields} Hq, q{bar q} {yields} Hg is compared to a similar cut for the background.
Date: August 15, 1993
Creator: Bailey, B. & Graudenz, D.
Partner: UNT Libraries Government Documents Department

CDF top results in the lepton + jets channel

Description: Results from the 1992--1993 Tevatron run (ran IA) top search at CDF in the lepton+jets channel are reported. The jet-vertexing algorithm tags 6 events on a background of 2.3 {plus_minus} 0.3 events in the W+ {ge} 3 jets data sample, and the soft lepton analysis finds T events on a background of 3.1 {plus_minus} 0.3 events in the same data sample. Jet-vertex and soft-lepton tag correlations are described. Also given are the expected and observed number of tags in the Z+mulitjet control sample.
Date: August 1, 1994
Creator: Watts, G. & Collaboration, CDF
Partner: UNT Libraries Government Documents Department

Search for excited quarks in p{bar p} collisions at {radical}s = 1.8 TeV

Description: If quarks are composite particles then excited states are expected in p{bar p} collisions. Using the CDF detector we have searched for excited quarks (q*) which decay to common quarks by emitting a W boson (q* {yields} qW) or a photon (q* {yields} q-{gamma}). In the W + jet and photon + jet mass spectra we see no compelling evidence for a q* mass resonance. We set an upper limit on the q* cross section vs. mass, and using the simplest model of excited quark production, we exclude excited quarks in the mass range 90 < M* < 570 GeV at 95% confidence level. This analysis is preliminary and only statistical uncertainties have been included.
Date: August 1, 1993
Creator: Collaboration, CDF
Partner: UNT Libraries Government Documents Department

Search for second generation leptoquarks at CDF

Description: We present the results of a search for second generation leptoquarks S{sub 2} in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron. This search is based on 19.3 pb{sup {minus}} of data collected during the 1992--93 CDF run. We have searched for evidence of leptoquark pairs assuming that ea& leptoquark decays to a muon+quark with a branching ratios. Two leptoquark candidate events were found with a background of 1.35{plus_minus}0.50. We obtained-upper limits on the production cross-section times branching ratio as a function of leptoquark mass. For pair production of second generation leptoquarks, we excluded M{sub S}{sub 2} < 133. GeV/c{sup 2} for {beta} = 100% and M{sup S}{sub 2} < 98 GeV/c{sup 2} for {beta} = 50% at 95% CL.
Date: August 1, 1994
Creator: Park, S. & Collaboration, CDF
Partner: UNT Libraries Government Documents Department

Top dilepton search at CDF

Description: The authors present preliminary results from a search for the top quark in the dilepton channel using data collected by CDF during the 1992--93 Fermilab Collider Run. The dilepton analysis implies a lower limit on the top quark mass of 113 GeV/c{sup 2} at the 95% confidence level, assuming Standard Model decays.
Date: August 1, 1993
Creator: Collaboration, The CDF
Partner: UNT Libraries Government Documents Department

Search for Z{prime} and W{prime} at CDF

Description: We have searched for heavy neutral and charged gauge bosons via the decays Z{prime} {yields} ee and W{prime} e{nu} in {bar p}p collisions at {radical}s = 1.8 TeV. The data were obtained using the CDF detector during 1992--1993 run corresponding to an integrated luminosity of 19.7{plus_minus}0.7 pb{sup {minus}1}. We present a 95% confidence level upper limit on the production cross section times branching ratio of Z{prime} and W{prime} as a function of Z{prime} and W{prime} mass. Assuming Standard Model coupling strengths, we exclude a Z{prime} with mass less than 505 GeV/c{sup 2} and a W{prime} with mass less than 652 GeV/c . We also present lower mass limits for Z{prime} bosons from E{sub 6} models and the Alternative Left-Right Model.
Date: August 1994
Creator: Maeshima, Kaori
Partner: UNT Libraries Government Documents Department

Search for AGN {nu}`s with the Soudan 2 detector

Description: We present a preliminary null result from a search for diffuse high energy neutrino emission by Active Galactic Nuclei. The method relies on the measurement of catastrophic energy loss by high energy muons in the Soudan 2 calorimeter. A Monte Carlo calculation of the energy loss of high energy muons is described.
Date: August 1, 1992
Creator: Ambats, I.; Ayres, D. S.; Balka, L. J.; Barrett, W. L.; Brock, T.; Dawson, J. W. et al.
Partner: UNT Libraries Government Documents Department

The search for top at CDF

Description: We present results on the search for the top quark in {bar p}p collisions at {radical}s = 1.8 TeV. The data sample collected during the 1988--89 run with the Collider Detector at Fermilab (CDF) includes more than 4 pb{sup {minus}1}. We report here on an extension of previously published searches for the top quark in electron + jets and the dilepton channel electron-muon. The 95% confidence level limit on the top mass is 89 GeV/c{sup 2}.
Date: August 1, 1991
Creator: Liss, T. M. & Collaboration, CDF
Partner: UNT Libraries Government Documents Department

A search for the top quark decaying to charged Higgs in p{bar p} collisions at {radical}s = 1.8 TeV

Description: We present results of a search for the top quark decaying to a charged. Higgs boson (H) in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron. Using 4.1 pb{sup {minus}1} of data collected during the 1988--1989 CDF run, we have searched for evidence of t{bar t} production assuming that t{r_arrow} Hb and H{r_arrow} {tau}{nu}{sub {tau}}. We find no evidence for this decay and are able to exclude regions in the (m{sub t}, m{sub H}) plane for different Br(H{r_arrow} {tau}{nu}{sub {tau}}). We also interpret these results for the two Higgs doublet(THD) model.
Date: August 1, 1993
Creator: Collaboration, CDF
Partner: UNT Libraries Government Documents Department

The discovery of the tau lepton: Part 1, The early history through 1975; Part 2, Confirmation of the discovery and measurement of major properties, 1976--1982

Description: Several previous papers have given the history of the discovery of the {tau} lepton at the Stanford Linear Accelerator Center (SLAC). These papers emphasized (a) the experiments which led to our 1975 publication of the first evidence for the existence of the {tau}, (b) the subsequent experiments which confirmed the existence of the r, and (c) the experiments which elucidated the major properties of the {tau}. That history will be summarized in Part 2 of this talk. In this Part 1, I describe the earlier thoughts and work of myself and my colleagues at SLAC in the 1960`s and early 1970`s which led to the discovery. I also describe the theoretical and experimental events in particle physics in the 1960`s in which our work was immersed. I will also try to describe for the younger generations of particle physicists, the atmosphere in the 1960`s. That was before the elucidation of the quark model of hadrons, before the development of the concept of particle generations The experimental paths to program we hot as clear as they are today and we had to cast a wide experimental net.
Date: August 1, 1994
Creator: Perl, M. L.
Partner: UNT Libraries Government Documents Department

A high rate transition radiation detector for particle identification in a hadron beam

Description: A Transition Radiation Detector (TRD) was built for the purpose of tagging beam particles in a high rate (/approximately/2 MHz) 250 GeV/c hadron beam during data taking for Experiment 769 at Fermilab. The availability of a good ''tool kit'', including a Monte Carlo program which could reliably predict the detector performance, made it possible to design and build the TRD in approximately one year. Pion or proton samples, each with a small contamination due to the other, could be selected with high efficiency by making cuts on the number of planes of the TRD registering hits for each incident beam particle. The detector is expected to work well to separate kaons from pions in the 500 GeV/c negative beam for E791. 15 refs., 8 figs., 1 tab.
Date: August 1, 1989
Creator: Errede, D.; Sheaff, M.; Fenker, H. & Mantsch, P.
Partner: UNT Libraries Government Documents Department

Results obtained using the Plastic Ball

Description: Single-particle inclusive experiments, and experiments that additionally measure a few correlations like the associated multiplicity, have provided the main contribution to our present understanding of high-energy heavy-ion collisions. The results from those experiments are in overall agreement with calculations of the cascade and hydrodynamical models. In the cascade model the collision of two nuclei is simulated as a cascade of nucleon-nucleon collisions using measured N-N cross sections. The hydrodynamical model, on the other hand, describes the nuclear collision as that of two fluids and makes use of a nuclear equation of state relating thermal and compressional energy densities to pressure. The pressure field dominates the expansion phase and leads to collective flow of the reaction products in a preferred direction. The observation of such effects in inclusive experiments is not well established. Collective effects that manifest themselves in the shape of the event in phase space are expected to be seen best in complete event detectors that measure the final state as exclusively as presently possible by measuring most of the charged particles emitted in the reaction. In addition, those detectors are well suited to test macroscopic concepts such as equilibrium and temperature. Global methods like the sphericity or thrust analysis take into account all the correlations measured in the event and are specially designed to determine the shape of an event in phase space and thus to define a reaction plane. Recent data from the Plastic Ball experiment about the study of nuclear stopping and thermalization and on global analysis are presented.
Date: August 1, 1983
Creator: Ritter, H.G.; Gustafsson, H.A. & Gutbrod, H.H.
Partner: UNT Libraries Government Documents Department

Z/sup 0/ decay modes - experimental measurements

Description: This report summarizes three lectures given at the Theoretical Advanced Study Institute at the University of Michigan at Ann Arbor. The lectures begin with an introduction to storage rings and linear colliders with special reference to the parameters of the SLC and LEP. The rigors of the Z/sup 0/ environment are presented along with the requirements for SLC and LEP detectors. The pedagogy needed for testing the Standard Model is developed, and some experimental tests of the Standard Model are discussed. Tests which involve extensions of the Standard Model (charged Higgs particles, more generations) as well as a few examples of how supersymmetry may show up at the Z/sup 0/ are discussed. 25 references, 34 figures. (WHK)
Date: August 1, 1984
Creator: Dorfan, J.M.
Partner: UNT Libraries Government Documents Department

The search for top at CDF

Description: We present results on the search for the top quark in {bar p}p collisions at {radical}s = 1.8 TeV. The data sample collected during the 1988--89 run with the Collider Detector at Fermilab (CDF) includes more than 4 pb{sup {minus}1}. We report here on an extension of previously published searches for the top quark in electron + jets and the dilepton channel electron-muon. The 95% confidence level limit on the top mass is 89 GeV/c{sup 2}.
Date: August 1, 1991
Creator: Liss, T.M. (Illinois Univ., Urbana, IL (United States). Loomis Lab. of Physics)
Partner: UNT Libraries Government Documents Department

B identification by topology with the SLD Detector

Description: At both the SLC and LEP large samples of Z/sup 0/ /yields/ b/bar b/ will soon be available. The challenge is to find experimental techniques to inclusively tag and identify the various particles b quarks may fragment into. The work described here makes use of the new generation of close-in tracking devices which will achieve unparalleled precision in particle trajectory resolution. Some of these devices provide three-dimensional information which is crucial in solving the pattern recognition problem discussed below. In the case where only two-dimensional information is available other than tracking information may be required. The tracking system is used to extrapolate tracks into some preselected point. The result is a picture of many crossing tracks and the problem is to find the real vertices among all the possible combinations. 1 ref., 3 figs., 1 tab.
Date: August 1, 1989
Creator: Atwood, W.B.
Partner: UNT Libraries Government Documents Department

Identifying the origin of new gauge bosons at the SSC and LHC

Description: The ability of an SCD-like detector to identify the origin of a new neutral gauge boson Z{sub 2}, once it has been discovered at the SSC and/or LHC, is examined. 9 refs., 3 figs.
Date: August 1, 1991
Creator: Hewett, J.L. (Argonne National Lab., IL (United States)) & Rizzo, T.G. (Argonne National Lab., IL (United States) Ames Lab., IA (United States))
Partner: UNT Libraries Government Documents Department

Evidence for B+ --> tau+ nu_tau Decays using Hadronic B Tags

Description: We present a search for the decay B{sup +} --&gt; {tau}{sup +} {nu}{sub {tau}} using 467.8 x 10{sup 6} B{anti B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. We select a sample of events with on completely reconstructed B{sup -} in an hadronic decay mode (B{sup -} --&gt; D{sup (*)0}X{sup -} and B{sup -} --&gt; J/{psi} X{sup -}). We examine the rest of the event to search for a B{sup +} --&gt; {tau}{sup +} {nu}{sub {tau}} decay. We identify the {tau}{sup +} lepton in the following modes: {tau}{sup +} --&gt; e{sup +} {nu}{sub e}{anti {nu}}{sub {tau}}, {tau}{sup +} --&gt; {mu}{sup +} {nu}{sub {mu}}{anti {nu}}{sub {tau}}, {tau}{sup +} --&gt; {pi}{sup +}{anti {nu}}{sub {tau}} and {tau}{sup +} --&gt; {rho}{anti {nu}}{sub {tau}}. We find an excess of events with respect to expected background, which excludes the null signal hypothesis at the level of 3.3 {sigma} and can be converted to a branching fraction central value of B(B{sup +} --&gt; {tau}{sup +} {nu}{sub {tau}})= (1.80{sup + 0.57}{sub - 0.54}(stat.) {+-} 0.26 (syst.)) x 10{sup -4}.
Date: August 11, 2011
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Progress on Development of the New FDIRC PID Detector

Description: We present a progress status of a new concept of PID detector called FDIRC, intended to be used at the SuperB experiment, which requires {pi}/K separation up to a few GeV/c. The new photon camera is made of the solid fused-silica optics with a volume 25x smaller and speed increased by a factor of ten compared to the BaBar DIRC, and therefore will be much less sensitive to electromagnetic and neutron background
Date: August 3, 2012
Creator: Vavra, Jerry
Partner: UNT Libraries Government Documents Department

Energy Spectra of Fragments from Silver and Uranium Bombarded with5.0 GeV Protons

Description: In this third paper in a series in which the characteristics of nuclear fragments produced in the interaction of 5 GeV protons with Ag and U targets were studied by means of dE/dx-E measurements with semiconductor detector telescopes new information was obtained on the energy spectra of light fragments. One set of measurements on fragments from a Ag target involved the use of a two-element telescope incorporating a {Delta}E detector as thin as 16 {micro}m. A new algorithm for processing the {Delta}E and E data to extract particle identification was developed and the resulting particle spectra showed superior resolution for the elements from Li(Z = 3) to S (Z = 16). Segments of the energy spectra of each of these elements were measured at 20{sup o} and, for many of them, also at 45{sup o}, 90{sup o}, 135{sup o} and 160{sup o} to the beam direction. By use of 3-element telescopes and absorbers the high energy part of the energy spectrum for isotopes of He, Li, Be, B, and C ejected from Ag and U targets was measured at 20{sup o}. The measurements extended beyond 300 MeV for {sup 6}Li and {sup 7}Li and to 400 MeV for {sup 7}Be. A distinct high-energy component was found in these cases. The suitability of nuclear evaporation as a description of the emission of the low-energy fragments was tested with two simple theoretical models, one specifying isotropic fragment emission from a moving nucleus at a fixed nuclear temperature and one specifying isotropic fragment emission from a set of moving nuclei with a Maxwellian distribution of excitation energies and forward momenta. The second could describe rather well all the 90{sup o} data, provided a Coulomb barrier 0.4 that of the classical tangent spheres barrier was used. However, the measured intensity in the forward direction ...
Date: August 1, 1972
Creator: Korteling, Ralph G.; Toren, C.R. & Hyde, Earl K.
Partner: UNT Libraries Government Documents Department