Electrons have been scattered inelastically from a hydrocarbon target containing protons polarized normal to the scattering plane. Scattered electrons with energies corresponding to the production of the Delta (1236), N(1512), and N(1688) pion-nucleon resonances were observed. A search was made for changes in the cross section as the target polarization was reversed. Any changes would have been evidence of a violation of time-reversal invariance in the electromagnetic interactions of the hadrons. No such changes were observed. With the maximum time-reversal-violating effect possible, the asymmetry would be 10 times the upper limit of this experiment. Early attempts at a coincidence-polarization experiment are described in an appendix.
Get full paper (pdf, 1254 KB)
Return to publication list
Send e-mail to author at kmh@hansonhub.com