The ratio of the proton's elastic electromagnetic form factors, , was obtained by measuring and , the transverse and the longitudinal recoil proton polarization, respectively. For elastic , is proportional to . Simultaneous measurement of and in a polarimeter provides good control of the systematic uncertainty. The results for the ratio show a systematic decrease as increases from 0.5 to , indicating for the first time a definite difference in the spatial distribution of charge and magnetization currents in the proton.
- Received 4 October 1999
- Published in the issue dated 14 February 2000
© 2000 The American Physical Society