|Author||Chiuderi, C. ♦ Morpurgo, G.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||PHYSICS ♦ CROSS SECTIONS ♦ DIFFERENTIAL EQUATIONS ♦ DIPOLES ♦ ELECTRIC FIELDS ♦ ENERGY RANGE ♦ GEV RANGE ♦ LAPLACE EQUATIONS ♦ LEAD ♦ LIFETIME ♦ MEASURED VALUES ♦ MULTIPOLES ♦ NUCLEAR MODELS ♦ NUMERICALS ♦ PHOTOPRODUCTION ♦ PIONS ♦ PIONS- NEUTRAL ♦ SUM RULES|
|Abstract||The possibility is suggested of determining the lifetime of the pi /sup o/ meson using pi /sup o/ photoproduction in a Coulomb field. Completition with coherent nuclear production necessitates a rather high photon energy. Even at 1 Bev, the Coulomb photoproduction dominates over the coherent nuclear one only in a very narrow cone around the forward direction. It must be shown further that the incoherent production is not dominant in this cone. Though the incoherent production is certainly smaller than the coherent nuclear one by a factor of A (= mass number), the incoherent cross section does not have the factor sin/sup 2/ theta which affects both the Coulomb and the nuclear coherent cross sections. A calculation of the incoherent photoproduction of pi /sup o/ at small angles is therefore made using a multipole expansion and sum miles. It is shown that, for lead, the incoherent cross section at small angles is at most of the same order of magnitude of the nuclear coherent one so that it does nct dominate the picture. For light nuclei the competition between incoherent and coherent nuclear production at small angles is more uafavorable and depends rather critically on the properties of the individual nucleus chosen. It is concluded that heavy nuclei are the most suited for this experiment and that, at 1 Bev, only lifetimes shorter than approximately 10/sup -16/ may be measured by this method. (auth)|
|Learning Resource Type||Article|
|Publisher Department||Universita, Florence|
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