Lady or tiger?-The Meitner-Hupfeld effect and Heisenberg's neutron theory
Abstract
Reports in May 1930 of an anomaly in the scattering and absorption of gamma rays, known as the Meitner-Hupfeld effect, presaged the New Physics of the 1930s. Scattering from light elements agreed with theoretical predictions based upon quantum electrodynamics and the relativistic electron theory of Dirac, but results on heavy targets pointed to a new nuclear absorption effect that was a harbinger of new particles and new phenomena. The experimental investigations of this anomalous absorption placed constraints on theories of nuclear structure, leading Heisenberg, for example, to insist upon the presence of electrons within nuclei as light as helium, even after Chadwick's discovery of the neutron and Heisenberg's proposed neutron-proton nuclear model. The anomalous γ-ray behavior was eventually ascribed to electron-positron pair production and annihilation.
- Publication:
-
American Journal of Physics
- Pub Date:
- February 1984
- DOI:
- 10.1119/1.13920
- Bibcode:
- 1984AmJPh..52..130B
- Keywords:
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- 25.20.Dc;
- 21.60.-n;
- 01.65.+g;
- Photon absorption and scattering;
- Nuclear structure models and methods;
- History of science