Angular Correlation of Photoproduced Pion Pairs

Author: Elliott, David Duncan

Year: 1959

Degree: Dissertation (Ph.D.)

Advisor: Sands, Matthew L.

Committee Member: Unknown, Unknown

Option: Physics; Mathematics

DOI: 10.7907/JQ7K-E986

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

The angular correlation between the two pions from the reaction [...] has been studied by observing coincidences between two pions produced simultaneously in a hydrogen target in the 1.1 Bev x-ray beam of the Cal Tech synchrotron. The negative pion was detected in a magnetic spectrometer set to accept 150 Mev pions at an angle, [...] 35° with respect to the x-ray beams. The positive pion was detected in a counter telescope which was set at various angles, [...] with respect to the x-ray beam, and at azimuthal angles, [...] with respect to the azimuthal angle of the negative pion, of 0°, 90°, and 180°. For each set of angles the absorbers between the counters of the telescope were chosen such that the observed pairs could be separated into two groups: those produced by photons with energies between 650 and 825 Mev, and those produced by photons with energies from 825 to the bremsstrahlung cut-off energy of 1080 Mev. For pairs produced by photons in the lower energy group the cross section shows no azimuthal dependence in the C. M. system within the statistical error of about [...] at either of the two C. M. zenith angles [...] = 70° and l20°. For a C. M. azimuthal angle of 180° the cross-section appears to be independent of zenith angle, [...] except at the most forward point ([...] = 35°) where the cross-section is about 30% larger than that observed at other angles. The value of the cross section integrated over all [...] directions is consistent with a direct measurement of the cross-section for the production of negative pions.

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