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Title: Structure of /sup 13/C studied by pion scattering near the (3,3) resonance

Thesis/Dissertation ·
OSTI ID:6208563

Good resolution (..pi../sup +/,..pi../sup +/') and (..pi../sup -/,..pi../sup -/') data were taken for many states in /sup 13/C using the Energetic Pion Channel and Spectrometer at the Los Alamos Meson Physics Facility. Differential cross sections were measured for angles between 20/sup 0/ and 105/sup 0/ at an incident pion energy of 162 MeV for the elastic scattering as well as for states at 3.09, 3.68, 3.85, 7.55, 8.86, 9.5, 11.82, 16.05, 17.92, 21.37, and 21.6 MeV. Excitation functions were measured for momentum transfers of q = 1.1 h-bar fm/sup -1/ and q = 1.4 h-bar fm/sup -1/, for energies between 100 and 300 MeV. A sigma(..pi../sup -/)/sigma(..pi../sup +/) ratio of 9:1 was observed for the first time, indicating a pure neutron particle-hole excitation of a high spin state (J/sup ..pi../ = 9/2/sup +/). Strikingly different energy dependences were found for ..delta..S = 0 and ..delta..S = 1 transitions. The data for all states were compared with the microscopic model calculations of Lee and Kurath. The excitation function data and comparisons with the microscopic model calculations were used to identify the states at 16.05, 17.92, 21.37, and 21.6 MeV as either 7/2/sup +/ or 9/2/sup +/ states. The elastic scattering data were analyzed with an optical model and the results were found to be consistent with neutron and proton distributions having equal rms radii. The optical potentials generated were used in a collective model analysis of the 3/2/sup -/(3.68 MeV) and 5/2/sup -/ (7.55 MeV) states. The reduced transition probabilities (B(E2)) derived from the proton parts of the transition strength are in agreement with those determined from electromagnetic measurements.

Research Organization:
Minnesota Univ., Minneapolis (USA)
OSTI ID:
6208563
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English