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Transverse and longitudinal Bose-Einstein correlations in antiproton-proton reactions at centre-of-mass energy 630 GeVOctober, Faith Joy 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: We use Hanbury-Brown Twiss interferometry to determine Bose-Einstein correlations in the
transverse and longitudinal directions. By using these two directions, we are able to determine
the shape of the pion emitting source. The analysis is done with the UA1 (1985) data for pp
collisions at Vs = 630 GeV. Two frames of reference, namely the laboratory frame and the
Longitudinal Center-of-Mass System (LCMS) are used. A fit to a two-dimensional Gaussian
parametrization yields good results.
In the laboratory frame, an oblate form of the source is observed, with the value of the
transverse radius (rt) larger than the longitudinal (rL) one. The LCMS analysis finds a prolate
form of the source (rt < rL). A few reasons are discussed for the difference in the shape between
the different reference frames. Our results are also compared with other hadron-hadron and
e+ e: experiments. / AFRIKAANSE OPSOMMING: Hanbury-Brown Twiss interferometrie was gebruik om Bose-Einstein korrelasies in die transversale
en longitudinale rigtings te bepaal. Deur hierdie twee rigtings te gebruik, kan die vorm van
die pion-bron bepaal word. Die UA1 (1985) datastel van die pp botsings by Vs = 630 GeV is
gebruik om die analise uit te voer. Twee verwysingstelsels, naamlik die laboratorium stelsel en
die Longitudinale Massamiddelpunt-stelsel is aangewend. 'n Passing met 'n twee-dimensionele
Gaussiese parametrisering het goeie resultate opgelewer.
In die laboratorium stelsel, is 'n ovaalvormige vorm vir die bron waargeneem, met die transversale
radius (rt) groter as die longitudinale radius (rl)' Die Longitudinale Massamiddelpunt stelsel
het 'n prolate vorm vir die bron voorspel, met rt < ri, 'n Paar redes vir die verskil in die vorm
van die pion-bron vir die verskillende verwysingstelsels word bespreek. Ons resultate word ook
met ander hadron-hadron en e+e- eksperimente vergelyk.
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Probing mSUGRA with a search for chargino-neutralino production using trileptonsGlatzer, Julian. January 2008 (has links)
Thesis (M.S.)--Rutgers University, 2008. / "Graduate Program in Physics and Astronomy." Includes bibliographical references (p. 117-121).
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Search for the Higgs Boson in H -] WW decays at the DØ experiment and precise muon trackingElmsheuser, Johannes. Unknown Date (has links) (PDF)
University, Diss., 2004--München.
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Search for large extra dimensions in the exclusive photon + missing energy channel in PP collisionsLazoflores, Jose A. Hagopian, V. Hagopian, Sharon. January 2006 (has links)
Thesis (Ph. D.)--Florida State University, 2006. / Advisors: Vasken Hagopian, Sharon Hagopian, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed Sept. 15, 2005). Document formatted into pages; contains xiv, 155 pages. Includes bibliographical references.
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A search for new physics in photon-lepton events in proton-antiproton collisions at [square root] S = 1.8 TeV /Berryhill, Jeffrey W. January 2000 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Physics, December 2000. / Includes bibliographical references. Also available on the Internet.
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Evidence for electroweak top quark production in proton-antiproton collisions at sqrt(s) = 1.96 TeV /Gadfort, Thomas, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 163-169).
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Antiproton proton annihilation in flight into K+K-0Uman, Ismail. Unknown Date (has links) (PDF)
University, Diss., 2001--München.
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Differentielle Wirkungsquerschnitte in Antiprotonen- und Protonen-Helium-StößenKhayyat, Khaldoun. Unknown Date (has links)
Universiẗat, Diss., 1998--Frankfurt (Main).
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PWO Crystal Measurements and Simulation Studies of Anti-Hyperon Polarisation for PANDAGrape, Sophie January 2008 (has links)
The Gesellschaft für Schwerionenforschung (GSI) facility in Darmstadt, Germany, will be upgraded to accommodate a new generation of physics experiments. The future accelerator facility will be called FAIR and one of the experimentsat the site will be PANDA, which aims at performing hadron physics investigations by colliding anti-protons with protons. The licentiate thesis consistsof three sections related to PANDA. The first contains energy resolutionstudies of PbWO4 crystals, the second light yield uniformity studies of PbWO4 crystals and the third reconstruction of the lambda-bar-polarisation in the PANDA experiment. Two measurements of the energy resolution were performed at MAX-Lab in Lund, Sweden, with an array of 3x3 PbWO4 crystals using a tagged photon beam with energies between 19 and 56 MeV. For the April measurement, the crystals were cooled down to -15 degrees C and for the September measurement down to -25 degrees C. The measured relative energy resolution, <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csigma" />/E, is decreasing from approximately 12% at 20 MeV to 7% at 55 MeV. In the standard energy resolution expression <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csigma" />/E = a/<img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csqrt%5B%5D%7BE%7D" /> <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" /> b/E <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" /> c, the three parameters a, b and c seem to be strongly correlated and thus difficult to determine independently over this relative small energy range. The value of a was therefore fixed to that one would expect from Poisson statistics of the light collection yield (50 phe/MeV) and the results from fits were <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csigma" />/E=0.45%/<img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csqrt%5B%5D%7BE_%7BGeV%7D%7D" /> <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" />0.18%/EGeV <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" />8.63% and <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csigma" />/E = 0.45%/<img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csqrt%5B%5D%7BE_%7BGeV%7D%7D" /><img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" />0.21%/EGeV <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" />6.12% for the April and September measurements, respectively. The data from the September measurement was also combined with previous data from MAMI for higher energies, ranging from approximately 64 to 715 MeV. The global fit over the whole range of energies gave an energy resolution expression of <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csigma" />/E = 1.6%/<img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Csqrt%5B%5D%7BE_%7BGeV%7D%7D" /> <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" />0.095%/EGeV <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Coplus" />2.1%. Light yield uniformity studies of five PbWO4 crystals, three tapered and two non-tapered ones, have also been performed. The tapered crystals delivered a light output which increased with increasing distance from the Photo Multiplier Tube (PM tube). Black tape was put on different sides of one tapered crystals, far from the PM tube to try to get a more constant uniformity prole. It was seen that the light output profile depends on the position of the tape. Generally, the steep increase in light output at large distances from the PM tube could be damped. The third part of the thesis concerns the reconstruction of the lambdabar polarisation in the reaction <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?pbar+p%20%5Crightarrow%20lambdabar%20+%20lambda" />. Events were generated using a modied generator from the PS185 experiment at LEAR. With a 100% polarisation perpendicular to the scattering plane, a polarisation of (99±1.8)% was reconstructed. Slight non-zero polarisations along the axis determined by the outgoing hyperon as well as the axis in the scattering plane, were also reconstructed. These were (4.1±2.1)% and (2.6±2.0)% respectively. From this investigation it was shown that the detector efficiency was not homogeneous and that slow pions are difficult to reconstruct.
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Measurements of Cosmic Ray Antiprotons with PAMELAWu, Juan January 2010 (has links)
QC 20100420
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