Coherent photoproduction of pi(+) from He-3

R. Nasseripour
B. L. Berman
W. J. Briscoe
H. Egiyan, William & Mary
K. A. Griffioen, William & Mary
B. Zhao, William & Mary


We have measured the differential cross section for the gamma He-3 ->pi(+)t reaction. This reaction was studied using the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Real photons produced with the Hall-B bremsstrahlung tagging system in the energy range from 0.50 to 1.55 GeV were incident on a cryogenic liquid He-3 target. The differential cross sections for the gamma He-3 ->pi(+)t reaction were measured as a function of photon-beam energy and pion-scattering angle. Theoretical predictions to date cannot explain the large cross sections except at backward angles, showing that additional components must be added to the model.