Antiproton-Proton Cross Sections at 133, 197, 265, and 333 Mev

Abstract

UCRL-8279In a scintillation-counter experiment the interaction of antiprotons with protons in the energy region 133 to 333 Mev has been studied. Antiprotons, produced internally in 'the Bevatron, channeled externally by a system of magnetic quadrupoles and bending magnets, and identified by time of flight, entered a tar get containing liquid hydrogen. This target was completely surrounded by a system of scintillation counters which detected both scattered antiprotons and annihilation .secondaries. An electrostaticmagnetic velocity spectrometer was used in the external magnetic channel to increase the ratio of antiprotons to pions. The p-p total, elastic, ineastic, and charge-exchange cross sections and the angular distribution of elastic scattering .were measured at each energy. The inelastic cross section is approximately one-half the total cross section at these energies.The results are discussed in connection with current theories.-3-< ANTIPROTON -PROTON GROSS SECTIONSAT 133, 197, 265, AND 333 Mev*

Antiproton Interactions in Hydrogen and Carbon below 200 Mev

“…mb at 133 ± 13 Mev in a -39-counter experiment. 9 Unfortunately, our bubble-chamber experiment permits little more than confirmation of the existence of the process.…”

“…Our results show support for the Ball-Chew theory on p scattering and annihilation, within the validity of our statistics. It should be pointed out that a recent counter experiment, 9 as well as accumulated emulsion results, 15 also lend verification to the theory. -6-The annihilation process is especially adapted to bubble chamber observation.…”

“…It requires only apparatus normally available at the Bevatron and was feasible before the construction of successful separators based on electrostatic deflection of particles. 9,19 A layout of the beam apparatus is shown in Fig. 1.…”

“…[2][3][4][5][6][7][8][9] In addition, a hydrogen-bubble-chamber experiment was recently performed. 10 A thorough review of the experimental and theoretical developments on antinucleons has been given recently by Segrè.…”

High-Energy Hadron--Deuteron Scattering.

“…Using as input the measured experimental data (Elioff et al, 1962;' Galbraith et al, 1965;Czyzewski et al, 1965;Coombes et al, 1958;Armenteros et al, 1960;Foley et al, 1963;Ferbel et al, 1965) on ..…”