Precision Measurement of the Charge Radius of the Proton.
Abstract
An accurate value for the proton charge radius is of fundamental importance in nuclear physics, both in tests of the accuracy of quantum electrodynamic calculations and as a new standard for comparison in nuclear physics experiments. Discrepancies between previous determinations of the proton radius are so large as to preclude useful tests of theory. Hence, the objective of this work is to obtain a new determination of the proton charge radius. There are two parts to this thesis, the first involving the collection of new and accurate data. The second part is a FourierBessel analysis of both the new and previous data and is the first thorough study of combined proton cross sections. The results are valuable for understanding the effect of different data sets upon the determination of the value of the proton charge radius and also lead to a better understanding of the limitations in the accuracy of quantum electrodynamic calculations. Absolute and relative to carbon cross sections for elastically scattering from hydrogen were obtained at the experimental facilities of the National Bureau of Standards. The data were obtained by using a highpressure, flowinggas targetcell that was alternatively filled with H_2 and CH_4 gas. To ensure the measurement of precise and accurate nuclear cross sections, control of many experimental parameters was required. The details concerning with control of the known experimental parameters and the careful treatment of these data are discussed in considerable detail. The determination of an accurate proton charge radius requires a combination of both the cross sections measured in this work and proton cross sections determined with larger momentum transfer. A parameterized Fourier Bessel charge density was fit to a large collection of experimental cross sections. This parameterized charge density has sufficient terms to accurately determine the proton charge radius for a set of cross sections spanning a momentum transfer range of 0.23 to 9.8 fm^ {1}. A best fit value obtained for the radius is 0.865(14) fm.
 Publication:

Ph.D. Thesis
 Pub Date:
 1989
 Bibcode:
 1989PhDT........66M
 Keywords:

 Physics: Nuclear