The Photoproduction of Positive Pions from Hydrogen at Energies of 1.1 to 1.4 GeV

Citation

Kilner, Joseph R. (1963) The Photoproduction of Positive Pions from Hydrogen at Energies of 1.1 to 1.4 GeV. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/G211-PZ76. https://resolver.caltech.edu/CaltechTHESIS:04202012-090651904

Abstract

A magnetic spectrometer and counter telescope system was used to detect positive pions photoproduced singly in a liquid hydrogen target. Measurements of the differential cross section were made at mean laboratory photon energies, k = 1.1, 1.2, 1.3, and 1.4 GeV and in the angular range from 5° to 165 ° in the center-of-momentum system of the pion.

The shape of the angular distribution of the differential cross sections at each value of k is very similar to that of the previously measured distribution at k = 1.0 GeV. The angular distributions were integrated to give the total cross sections. The third pion-nucleon "resonance" peak is seen to be very close to k = 1.0 GeV. A leveling off of the total cross section at k = 1.4 GeV may be due to the fourth "resonance".

The accurate small angle data at k = 1.1 and 1.2 GeV permitted a reasonable extrapolation of the differential cross section to the pion-nucleon pole. The value of the pion-nucleon coupling constant, f, was extracted from this extrapolation. The result was f^2 = 0.078 ± 0.011.

Thesis Files