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Il Nuovo Cimento A (1971-1996)

, Volume 48, Issue 2, pp 320–333 | Cite as

Yet another proposal for determining the induced pseudoscalar coupling constant

  • A. Maksymowicz
Article

Summary

It has been known for some time that μ capture from the O+ ground state of16O to the first excited O level of16N could, in principle, provide an accurate measurement of the induced pseudoscalar coupling constant in weak interactions. However, the calculation of the rate of this reaction has been hampered by the lack of an accurate wave function for the16N(0) state. We propose that this difficulty could be circumvented by a measurement of the rate of the β-decay from the16N(0) state back to the16O(0+) ground state. The ratio of the μ-capture to β-decay rates turns out to be almost independent of the details of the nuclear wave function and thus should allow a reasonably accurate determination of the induced pseudoscalar coupling constant to be made.

Ещё одно предложение для определения введенной псевдоскалярной константы связи

Резюме

В течение некоторого времени было известно, что μ-захват из основного 0+ состояния16O на первый возбужденный 0 уровень16N может, в принципе, обеспечить аккуратное измерение введенной псевдосклярной константы связи в слабых взаимодействиях. Однако, вычисление скорости этой реакции было затру-днено из-за недостаточно точного знания волновой функции для16N(0) состояния. Мы предлагаем, что эту трудность можно обойти если измерять скорость β-распада из состояния16N(0) обратно в основное состояние16O(0+). Отношение скоростей μ-захвата и β-распада оказывается почти не зависит от структуры ядерной волновой функции и, следовательно, возможно произвести довольно аккуратное определение введенной псевдоскалярной константы связи.

Riassunto

È noto da qualche tempo che la cattura di μ dallo stato fondamentale 0+ del16O al primo livello 0 eccitato di16N potrebbe, in linea di principio, fornire una misura accurata della costante di accoppiamento pseduoscalare indotto nelle interazioni deboli. Però il calcolo del rapporto di questa reazione è stato ostacolato dalla mancanza di un'accurata funzione d'onda dello stato16N(0). Si propone di superare questa difficoltà misurando il rapporto del decadimento β dallo stato16N(0) allo stato fondamentale16O(0+). La relazione fra i rapporti della cattura di μ e del decadimento β risulta pressocché indipendente dai dettagli della funzione d'onda nucleare e perciò dovrebbe permettere di fare una determinazione ragionevolmente accurata della costante dell'accoppiamento pseudoscalare indotto.

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References

  1. (1).
    I. S. Shapiro andL. D. Blokhintsev:Žurn. Ėksp. Teor. Fiz.,39, 1112 (1960) (English translation:Sov. Phys. JETP,12, 775 (1961).Google Scholar
  2. (2).
    T. Ericson, J. C. Sens andH. P. C. Rood:Nuovo Cimento,34, 51 (1964).CrossRefGoogle Scholar
  3. (3).
    V. Gillet andD. A. Jenkins:Phys. Rev.,140, B 32 (1965).ADSCrossRefGoogle Scholar
  4. (4).
    A possible pseudotensor coupling has been excluded by requiring that only first-class currents contribute to the interaction Hamiltonian. See,S. Weinberg:Phys. Rev.,112, 1375 (1958).ADSCrossRefGoogle Scholar
  5. (5).
    I. Duck:Nucl. Phys.,35, 27 (1962).CrossRefGoogle Scholar
  6. (6).
    The relevance of such a measurement for the determination ofg P was first suggested by Drs.J. Deutsch andP. Macq. (Private communication to the author by Dr.N. Cabibbo).Google Scholar
  7. (7).
    F. Ajzenberg-Selove andT. Lauritsen:Nucl. Phys.,11, 203 (1959).CrossRefGoogle Scholar
  8. (8).
    We consider here only the axial vector and pseudoscalar contributions to the interaction Hamiltonian.Google Scholar
  9. (9).
    J. R. Luyten, H. P. C. Rood andH. A. Tolhoek:Nucl. Phys.,41, 236 (1963).CrossRefGoogle Scholar
  10. (10).
    G. E. Lee-Whiting:Can. Journ. Phys.,36, 1199 (1958).ADSCrossRefGoogle Scholar
  11. (11).
    E. Greuling:Phys. Rev.,61, 568 (1942).ADSCrossRefGoogle Scholar
  12. (12).
    J. P. Elliott andB. H. Flowers:Proc. Roy. Soc., A242, 57 (1957).ADSCrossRefGoogle Scholar
  13. (13).
    V. Gillet andN. Vinh Mau:Nucl. Phys.,54, 321 (1964).CrossRefGoogle Scholar
  14. (14).
    R. C. Cohen, S. Devons andA. D. Kanaris:Nucl. Phys.,57, 255 (1964).CrossRefGoogle Scholar
  15. (15).
    A. I. Astbury, L. D. Auerbach, D. Cutts, R. J. Esterling, D. A. Jenkins, N. H. Lipman andR. E. Shafer:Nuovo Cimento,33, 1020 (1964).CrossRefGoogle Scholar
  16. (16).
    We have estimated these values from Fig. 3 of ref. (3). In making this estimate only the experimental uncertainty in the capture rate was taken into account. For consistency with the rest of the paper we have used the sign convention of ref. (2) forX 2; the opposite signs are used in ref. (3).ADSCrossRefGoogle Scholar
  17. (17).
    H. F. Ehrenberg, R. Hofstadter, U. Meyer-Berkhout, D. G. Ravenhall andS. E. Sobotka:Phys. Rev.,113, 666 (1959).ADSCrossRefGoogle Scholar
  18. (18).
    G. Brunhart, V. P. Kenney andB. D. Kern:Phys. Rev.,110, 924 (1956).ADSCrossRefGoogle Scholar
  19. (19).
    W. W. Givens, T. W. Bonner, S. H. Fang, R. C. Bearse andA. A. Rollefson:Nucl. Phys.,46, 504 (1963).CrossRefGoogle Scholar
  20. (20).
    H. Crannell:Elastic and inelastic electron scattering from 12Cand 16O, HEPL 410, High-Energy Physics Laboratory, Stanford University, January (1966).Google Scholar
  21. (21).
    C. P. Bhalla:Phys. Lett.,19, 691 (1966).ADSCrossRefGoogle Scholar
  22. (22).
    H. P. C. Rood:The coupling constants in muon capture, to be published inSuppl. Nuovo Cimento.Google Scholar

Copyright information

© Società Italiana di Fisica 1967

Authors and Affiliations

  • A. Maksymowicz
    • 1
  1. 1.CERNGeneva

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