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Spontaneous breakdown of conformal and chiral invariance


Crewther, Rodney James (1971) Spontaneous breakdown of conformal and chiral invariance. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/CSW2-C047.


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We discuss the implications of a theory in which scale and chiral invariance are spontaneously broken, and the dilaton [...] appears as a mixture of the two isoscalar members of the scalar nonet. From standard assumptions for the conformal properties of the axial-vector current, we predict the ratio of the [...] and [...] coupling constants, and test the hypothesis of f-dominance. At first, we neglect the effects of scale violation. Then, the calculated width of the dilaton, [...], appears to exceed the limit given by the Adler-Weisberger sum rule for [...] scattering, while f-dominance seems to work. Using the method of collinear dispersion relations, we estimate scalebreaking effects, which are found to be large. In the real world, our result for [...] agrees with other expectations, both experimental and theoretical. However, the spin-2 gravitational radius of the pion is found to be double the prediction of f-dominance. This is consistent with experimental indications that f-dominance fails. We discuss meson-baryon scattering and its relation to parameters measuring the breaking of chiral symmetry in the energy density. Our interpretation of a recent result of Cheng and Dashen is that scale invariance is spontaneously broken, and chiral SU(2) x SU(2) is a much better summetry than SU(3). By requiring consistency, with a sum rule of von Hippel and Kim, we find that data for [...] scattering are not consistent with the dimension of the chiral-violating scalar being -1.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:broken scale invariance; chiral symmetry; dilaton; Goldstone bosons
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Mann, Murray Gell
Thesis Committee:
  • Unknown, Unknown
Defense Date:28 May 1971
Record Number:CaltechETD:etd-11182004-132951
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4596
Deposited By: Imported from ETD-db
Deposited On:18 Nov 2004
Last Modified:21 Dec 2019 04:47

Thesis Files

PDF (Crewther_rj_1971.pdf) - Final Version
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