Book contents
- Frontmatter
- Contents
- List of contributors
- Foreword by Leon M. Lederman
- Editors' acknowledgments
- Photographs of the symposium
- List of abbreviations
- List of notation
- I Introduction
- II Particle discoveries in cosmic rays
- III High-energy nuclear physics
- 6 Learning about nucleon resonances with pion photoproduction
- 7 A personal view of nucleon structure as revealed by electron scattering
- 8 Comments on electromagnetic form factors of the nucleon
- IV The new laboratory
- V The strange particles
- VI Weak interactions
- VII Weak interactions and parity nonconservation
- VIII The particle physics community
- IX Theories of hadrons
- X Personal overviews
- Name index
- Subject index
8 - Comments on electromagnetic form factors of the nucleon
Published online by Cambridge University Press: 07 May 2010
- Frontmatter
- Contents
- List of contributors
- Foreword by Leon M. Lederman
- Editors' acknowledgments
- Photographs of the symposium
- List of abbreviations
- List of notation
- I Introduction
- II Particle discoveries in cosmic rays
- III High-energy nuclear physics
- 6 Learning about nucleon resonances with pion photoproduction
- 7 A personal view of nucleon structure as revealed by electron scattering
- 8 Comments on electromagnetic form factors of the nucleon
- IV The new laboratory
- V The strange particles
- VI Weak interactions
- VII Weak interactions and parity nonconservation
- VIII The particle physics community
- IX Theories of hadrons
- X Personal overviews
- Name index
- Subject index
Summary
These comments are intended to provide some historical background to a point that Robert Hofstadter touched on in Chapter 7. The point concerns the remark following his equation (7.4), to the effect that the nonrelativistic physical interpretation of the form factors as a Fourier transform of the charge density “could not hold at the short distances within the proton.” One of us (R.G.S.) took an interest in this specific problem after hearing Hofstadter raise the same issue in a presentation of his work many years ago. At that time he called for some valid physical interpretation of the form factors in the relativistic region, corresponding to this nonrelativistic interpretation. As Hofstadter has often suggested, it is useful to have a physical insight into the meaning of the form factors in order to further their interpretation in terms of the structure of the nucleon.
After the static magnetic moments, the electron–nucleon (e–N) interaction in the limit of q2 = 0 (q is the momentum transfer) was the first measurement that gave information about the extended structure of the nucleon. Leslie L. Foldy made the interesting observation that this e–N interaction could be attributed to the anomalous magnetic moment of the neutron. His calculation was based on a relativistic Hamiltonian, which he then extended by assuming that a complete effective relativistic Hamiltonian could be written as a power series in the d'Alembertian operator.
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- Information
- Pions to QuarksParticle Physics in the 1950s, pp. 144 - 146Publisher: Cambridge University PressPrint publication year: 1989