Abstract
A precision measurement with the SIN bent-crystal spectrometer of the wavelength of the transition in muonic yields pm, the accuracy being an order of magnitude higher than that of earlier investigations. The rms charge radius of is deduced as fm, differing by 2.4 standard deviations from the most accurate electron-scattering results. Consequences of attributing this discrepancy to a interaction beyond QED are discussed.
- Received 5 May 1982
DOI:https://doi.org/10.1103/PhysRevLett.49.859
©1982 American Physical Society