Accession Number : AD0463449

Title :   PHOTOPRODUCTION OF PI O FROM HYDROGEN NEAR THE SECOND PION NUCLEON RESONANCE,

Corporate Author : STANFORD UNIV CA HIGH ENERGY PHYSICS LAB

Personal Author(s) : De Staebler, H., Jr. ; Erickson, E. F. ; Hearn, A. C. ; Schaerf, C.

Report Date : FEB 1965

Pagination or Media Count : 51

Abstract : Pion photoproduction from nucleons has proved a useful tool in the study of the pion-nucleon interaction because of the dominance of the strong final-state interaction between emitted pion and recoil nucleon. There has remained, however, a noticeable lack of data at high momentum transfer in the region of the second pion-nucleon resonance. In particular, the zero angle measurement provides an important test of the hypothesis that the direct photo-electric term is responsible for the difference in position of this resonance in pi o and pi = photoproduction. The present experiment was designed to study this region using the Stanford Mark III linear accelerator. The results of the experiment establish that the discrepancy in resonance positions is not due to the photo-electric term, and also establish the possibility of a high momentum transfer enhancement of pi o photoproduction caused by crossed nucleon and nucleon isobar exchanges. The paper is divided into into five parts. In Section II, the experimental equipment and techniques are described. Section III contains an account of the data reduction, and the results are then interpreted in Section IV. Finally, in Section V, general conclusions are drawn. (Author)

Descriptors :   (*NUCLEAR RESONANCE, EXPERIMENTAL DATA), NUCLEONS, PIONS, LINEAR ACCELERATORS, TEST METHODS, TEST EQUIPMENT, PHOTOELECTRIC EFFECT(GAMMA RAYS), PHOTONUCLEAR REACTIONS, ELECTRON BEAMS, GAMMA RAYS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE