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Comparison of the Beta-Spectra of Boron 12 and Nitrogen 12


Hilton, Henry Hoyt (1960) Comparison of the Beta-Spectra of Boron 12 and Nitrogen 12. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/W0PW-BR58.


This thesis, a "Comparison of the Beta-Spectra of Boron 12 and Nitrogen 12," is an attempt to test the nature of the vector interaction in beta-decay. The ratio of the matrix elements of the Boron 12 and Nitrogen 12 beta-decays is expected theoretically to have an energy dependence of the form (1 + 16/3 aE), where a is of the order of 2/M for the Conserved Vector Current Theory in which the virtual pions surrounding the nucleons carry the beta-decay charge, and is of the order of 2/5M for the Fermi Theory in which the virtual pions do not. Inserting for M the value of the nucleon mass, the expected energy dependences are 1.41%/Mev and 0.3%/Mev. Two separate determinations of this energy dependence were made by measuring the momentum spectra of the two beta-decays. The first gave 0.2 ± 1.2%/Mev, and the second gave 3.1 ± 1.2%/Mev. About half of these errors are systematic, and are the same for both experiments. Hence it seems wiser not to average the two experiments. The Conserved Vector Current Theory seems slightly favored by these two experiments.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Gell-Mann, Murray (advisor)
  • Feynman, Richard Phillips (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1960
Record Number:CaltechETD:etd-06222006-090249
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2687
Deposited By: Imported from ETD-db
Deposited On:30 Jun 2006
Last Modified:23 Oct 2023 22:57

Thesis Files

PDF (Hilton_hh_1960.pdf) - Final Version
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