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Author Chamberlain, H. O. ♦ Goldhaber, G. ♦ Jauneau, L. ♦ Kalogeropoulos, T. ♦ Segre, E. ♦ Silberberg, R.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS AND MATHEMATICS ♦ ANNIHILATION ♦ ANTIPROTONS ♦ BETATRONS ♦ BEVATRON ♦ CROSS SECTIONS ♦ ENERGY RANGE ♦ EXCITATION ♦ HYDROGEN ♦ INTERACTIONS ♦ KAONS ♦ NUCLEAR EMULSIONS ♦ NUCLEI ♦ NUCLEONS ♦ PARTICLE MODELS ♦ PARTICLE TRACKS ♦ PIONS ♦ PROTON BEAMS ♦ PROTONS ♦ SYNCHROTRONS
Abstract Work was continued on antiproton interactions in photographic emulsions. Most of the data come from an exposure at the Bevatron to an enriched antiproton beam of 700 Mev/c momentum. An analysis of 221 antiproton stars is presented, 95 of which occurred in flight. An average antiproton cross section of (1.9 sintering time 0.2) mpacting /sub 0/, where mpacting /sub 0/ = The effects of (1.2 x 10/sup -13/A/sup 1/3/)/sup 2/, for all the elements in emuosion was founds excluding hydrogen. The primary antiproton annihilation gives rise to 5.36 sintering time 0.3 pions on the average. Inihilations at rest, 1.3 of the pions formed interact with the parent nucleus; in reactions in flight, 1.9 of the pions. For stars at rest the energy available in the annihilation in complex nuclei is divided up among the products as follows: charged pions, 48 sintering time 6%, neutral particles (other than neutrons and K/sub 0/ mesons) 28 sintering time 7%; K mesons 3 sintering time 1.5%; and cascade nucleons and nuclear excitation 21 sintering time 2%. For the stars in flight the corresponding percentages are: 45 sintering time 7, 22 sintering time 7, 3 sintering time 1.5, and 10 sintering time 2%. To fit the average pion multiplicitys the interaction radius of the Fermi statistical model must be taken as 2.5h/m The effects of c. Other proposals to explain the large multiplicity are discussed. From the fraction of pions interacting in the same nucleus, it is deduced that the annihilation takes place at the outer fringes of the nucleus. (auth)
ISSN 0031899X
Educational Use Research
Learning Resource Type Article
Publisher Date 1959-03-15
Publisher Department Univ. of California, Berkeley
Journal Physical Review
Volume Number 113
Organization Univ. of California, Berkeley


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