Thesis (Ph. D. in Physics)--University of California, Berkeley, Sept. 1960. / Includes bibliographical references (leaves 87-90).

Thesis (Ph. D. in Physics)--University of California, Berkeley, October 1956. / Also issued by University of California Radiation Laboratory. Includes bibliography references.

The cross sections for muon pair production in antiproton-nucleus and pion-nucleus collisions have been measured using a 125 GeV/c beam incident on a tungsten target. Both cross sections agree well with data scaled from other beam energies. The measured cross section for antiproton produced pairs is a factor of K = 2.45 larger than the predictions of the Drell-Yan model using structure functions measured by deep inelastic lepton scattering experiments. / The Drell-Yan formula has been inverted and the antiproton and pion valence structure functions have been extracted from the data. The shape of the antiproton structure function agrees well with the shape of the proton structure function measured by deep inelastic scattering experiments. The shape and magnitude of both the antiproton and the pion structure functions agree well with measurements made by other muon pair experiments.

Thesis (Ph. D. in Physics)--University of California, Berkeley, April 1960. / Includes bibliographical references (p. 73-76).

No description available.

The LEAP (Low-Energy Antiproton) experiment is a search for cosmic-ray antiprotons in the 120 MeV to 1.2 GeV kinetic energy range. The motivation for this project was the result announced by Buffington et al. (1981) that indicated an anomalously high antiproton flux below 300 MeV; this result has compelled theorists to propose sources of primary antiprotons above the small secondary antiproton flux produced by high energy cosmic-ray collisions with nuclei in the interstellar medium. LEAP consisted of the NMSU magnet spectrometer, a time-of-flight system designed at Goddard Space Flight Center, two scintillation detectors, and a Cherenkov counter designed and built at the University of Arizona. Analysis of flight data performed by the high-energy astrophysics group at Goddard Space Flight Center revealed no antiproton candidates found in the 120 MeV to 360 MeV range; 3 possible antiproton candidate events were found in the 500 MeV to 1.2 GeV range in an analysis done here at the University of Arizona. However, since it will be necessary to sharpen the calibration on all of the LEAP systems in order to positively identify these events as antiprotons, only an upper limit has been determined at present. Thus, combining the analyses performed at the University of Arizona and Goddard Space Flight Center, 90% confidence upper limits of 3.5 x 10⁻⁵ in the 120 MeV to 360 MeV range and 2.3 x 10⁻⁴ in the 500 MeV to 1.2 GeV range for the antiproton/proton ratio is indicated by the LEAP results. LEAP disagrees sharply with the results of the Buffington group, indicating a low antiproton flux at these energies. Thus, a purely secondary antiproton flux may be adequate at low energies.

Thesis--University of California, Berkeley, 1959. / "Physics and Mathematics" -t.p. Includes bibliographical references (p. 63-64).

No description available.

New measurements of the antiproton flux and the antiproton-to-proton flux ratio at the top of the atmosphere between 80 MeV and 2.0 GeV are presented. The measurement was conducted from July 2006 to March 2008 with the PAMELA satellite experiment. This is a period of minimum solar activity and negative solar polarity and the PAMELA measurement is the first observation of antiprotons during this particular solar state. The PAMELA instrument comprises a permanent magnet spectrometer, a scintillator based time-of-flight system, an electromagnetic calorimeter and an anticoincidence shield. These detectors can identify antiprotons from a background of cosmic-ray electrons and locally produced pions. The PAMELA instrument is mounted on the Resurs DK1 satellite that was launched from the Baikonur Cosmodrome on June the 15th into a semi-polar orbit with an inclination of 70o. During approximately 500 days of data collection 170 antiprotons were identified. The derived antiproton spectrum shows a steep increase up to 2 GeV as expected for pure secondary production of galactic antiprotons. The antiproton flux is over-estimated by most current models of secondary production compared to PAMELA results. There are no indications of the excess of antiprotons at low energy predicted by theories of primordial black hole evaporation. The antiproton-to-proton flux ratio is in agreement with drift models of solar modulation, which are also favoured by recent PAMELA measurements of the positron fraction. / QC 20100811

No description available.