Advertisement

Parity Violation Effect in Atomic Physics and the Structure of Neutral Currents in Gauge Theories

  • T. C. Yang
Chapter
Part of the NATO Advanced Study Institutes Series book series (NSSB, volume 39)

Abstract

We study here three models, namely, the SU(2) \( \otimes \) U(1) model, the SUL(2) \( \otimes \) SUR(2) \( \otimes \) U(1) model and the SUL(2) \( \otimes \) SUL(2) \( \otimes \) U(1) model, which seem to be the most natural extensions of the Weinberg-Salam model in order to accomodate the recent atomic Bismuth experimental results. The differences between the model predictions in neutrino reactions are small except for the elastic υμe and υμe cross sections. We remark on the other specific experiments which could provide meaningful checks between these models. We also comment on the “naturalness” of each model.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References and Footnotes

  1. 1.
    S. Weinberg, Phys.Rev.Lett. 19, 1264 (1967). Abdus Salam, in Elementary Particle Physics, edited by N. Svartholm ( Almquist and Wikskells, Stockholm, 1968 ), p. 367.Google Scholar
  2. 2.
    S.L. Glashow, J. Iliopoulos, and L. Maiani, Phys.Rev. D2, 1285 (1970).ADSGoogle Scholar
  3. 3.
    See the lectures given by J. Steinberger.Google Scholar
  4. 4.
    See the lectures given by V. Telegdi. One should bear in mind that in heavy atoms like Bismuth, the time component of the hadronic neutral currents are enhanced by the atomic numbers. What the present experiments have measured is thus the parity violation effect induced by the vector hadronic neutral currents and the axial-vector electron currents.Google Scholar
  5. 5.
    E.N. Henley and L. Wilets, Phys.Rev. A14, 1411 (1976); M. Brimicombe, C.E. Loving and P.G.H. Sandars, J. Phys. (London), B9, L237 (1976); I.B. Khriplovich, JETP Lett., Vol. 20, 315 (1974).ADSGoogle Scholar
  6. 6.
    The latest results reported by P.G.H. Sanders at International Symposium on Lepton and Photon Interactions at High Energies, Hamburg (1977) are R648nm = (-0.7 ± 3.2) x 10-8 (U. of Washington Experiment) and R648nm ~ -23 x 10-8 (Oxford Experiment).Google Scholar
  7. 7.
    P. Fayet, Nucl.Phys. B78, 14 (1974); T.P. Cheng and L.-F.Li, Phys.Rev. Lett. 38, 381 (1977). Fayet first proposed that the weak electron current should be pure vector. This model was noted by Cheng and Li with regard to μ →eγ decay.ADSCrossRefGoogle Scholar
  8. 8.
    R.N. Mohapatra and D.P. Sidhu, Phys.Rev.Lett. 38, 667 (1977) and to be published; A. De Rujula, H. Georgi and S.L. Glashow, to be published; J.C. Pati, S. Rajpout and A. Salam, ICTP preprint ICTP/76/11; J.C. Pati and A. Salam, Phys.Rev. D10, 275 (1974); R.N. Mohapatra and J.C. Pati, Phys.Rev. D11, 566, 2558 (1975); H. Fritzch and P. Minkowski, Nucl.Phys.B103, 61 (1976); E. Ma, Oregon preprint OITS-68 (to be published); S. Weinberg, Phys. Rev. Lett. 29, 388 (1972).ADSCrossRefGoogle Scholar
  9. 9.
    T.C. Yang, DESY 77/39, to be published and DESY preprint 77/51.Google Scholar
  10. 10.
    See the lectures given by J. Ellis. Naturalness condition was first proposed by S.L. Glashow and S. Weinberg, Phys. Rev. D15, 1958 (1977).CrossRefGoogle Scholar
  11. 11.
    See the lectures given by L. Lederman.Google Scholar
  12. 12.
    For recent results, see H. Reithler reported at International Symposium on Lepton and Photon Interactions at High Energies, Hamburg (1977).Google Scholar
  13. 13.
    A. McDonald, Nucl.Phys. B75, 343 (1974) and references therein.ADSCrossRefGoogle Scholar
  14. 14.
    R. Gatto and G. Preparata, Nuovo Cimento Letters 7, 89 (1973) and ref. 13.CrossRefGoogle Scholar
  15. 15.
    8 quarks and 8 leptons were previously proposed in a different context (see T.C. Yang, Phys.Lett. 65B, 358 (1976)). We received a recent preprint by N.A.B. Bég, R.N. Mohapatra, A. Si lin and H.-S. Tsao who have discussed 8 quarks and 24 leptons in a SUL (4) \( \otimes \) SUR (4) \( \otimes \) U(1) model. Note that under SU(4) symmetry, 8 quarks would require 24 leptons in order to cancel anomalies.CrossRefGoogle Scholar
  16. 16.
    The main point is that t, b, g, h quarks are heavier than \(\tau \) lepton. The \(\tau \) decay via “flavor” SU(2) interactions is just like the case of a sequential heavy lepton. The only place where the “fragrance” interaction contributes is in \(\tau \,\, \to \,\,e{\nu _e}{\nu _\tau }\). We thus find that \(\frac{{BR\left( {\tau \to {\nu _\tau }e{{\mathop \nu \limits^ - }_e}} \right)}}{{BR\left( {\tau \to {\nu _\tau }\mu \,\,\mathop {{{\mathop \nu \limits^ - }_\mu }}\limits^{} } \right)}}\,\, \ne \,\,1\) Google Scholar
  17. 17.
    P.Q. Hung and J.J. Sakurai, Phys.Lett. 63B, 295 (1976).CrossRefGoogle Scholar
  18. 18.
    L.M. Sehgal, Nucl. Phys. B90, 471 (1975) and references therein.ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1979

Authors and Affiliations

  • T. C. Yang
    • 1
  1. 1.Deutsches Elektronen-Synchrotron DESYHamburgGermany

Personalised recommendations