Summary
The parity-non-conserving, V-A form of Fermi interaction is derived from a principle of invariance under a continuous group of transformations, in analogy with the ordinary gauge-invariance derivation of the minimal electromagnetic interaction of charged particles. This assumption is a stronger restriction on the form of Fermi interactions than that invoked bySudarshan andMarshak, Gell-Mann andFeynman, andSakurai, and leads to additional predictions that are subject to experimental check. If these transformations were symmetry transformations of the entire Lagrangian, then the β- and μ-decay coupling constants would be precisely equal. The implications of extending this Fermi gauge invariance to a group depending on space-time functions is discussed. The possibility that Fermi interactions involving change of strangeness are unallowed is considered, and the results of assuming a universal Yukawa V-A parity-non-conserving interaction are tabulated. Such a Yukawa interaction, involving one new coupling constant, leads to reasonable K-meson and hyperon decay rates and allows π-meson decay into μ+ν without any appreciable decay into e+ν.
Riassunto
La forma V-A dell’interazione di Fermi non conservante la parità si deriva da un principio d’invarianza rispetto a un gruppo continuo di trasformazioni in analogia colla derivazione ordinaria dell’invarianza di gauge della minima interazione elettromagnetica delle particelle cariche. Questa ipotesi è per la forma delle interazioni di Fermi una restrizione più severa di quella invocata daSudarshan eMarshak, Gell-Mann eFeynman, eSakurai e conduce ad ulteriori predizioni suscettibili di verifica sperimentale. Se queste trasformazioni fossero trasformazioni della simmetria dell’intera lagrangiana, le costanti di accoppiamento del decadimento β e μ sarebbero esattamente uguali. Si discutono le conseguenze derivanti dall’estensione di questa invarianza di gauge secondo Fermi a un gruppo dipendente da funzioni dello spazio-tempo. Si considera la possibilità che le interazioni di Fermi che comportino un cambiamento di stranezza siano proibite, e si tabulano i risultati derivanti dall’ipotesi di una interazione universale V-A di Yukawa non conservante la parità. Tale interazione di Yukawa, che richiede una nuova costante di accoppiamento conduce a ragionevoli tassi di decadimento dei mesoni K e degli iperoni e permette il decadimento dei mesoni π in μ + v senza apprezzabile decadimento in e + v.
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References
G. Puppi:Nuovo Cimento,5, 587 (1948);O. Klein:Nature,161, 897 (1948);T. D. Lee, M. Rosenbluth andC. N. Yang:Phys. Rev.,75, 905 (1949);J. Tiomno andJ. Wheeler:Rev. Mod. Phys.,21, 153 (1949).
E. C. G. Sudarshan andR. E. Marshak:Padua-Venice International Conference, September, 1957;Phys. Rev.,109, 1860 (1958).
R. P. Feynman andM. Gell-Mann:Phys. Rev.,109, 193 (1958).
J. J. Sakurai:Nuovo Cimento,7, 649 (1958).
M. Gell-Mann:Suppl. Nuovo Cimento,4, 848 (1956).
T. D. Lee andC. N. Yang:Phys. Rev.,108, 1611 (1957).
S. Bludman andA. Klein:Phys. Rev.,109, 559 (1958).
C. P. Sargent, M. Rinehart, L. M. Lederman, andK. G. Rogers:Phys. Rev.,99, 885 (1955);K. Crowe:Bull. Am. Phys. Soc., Ser. II,2, 206 (1957);L. Rosenson:Phys. Rev,.109, 958 (1958).
This observation is originally due toR. Gatto,UCRL: (private communication).
See the review byL. Michel:Rev. Mod. Phys.,29, 223 (1957).
R. Finkelstein andS. A. Moszkoswki:Phys. Rev.,95, 1695 (1954);S. S. Gerschtein andIa. B. Zel’dovich:Soviet Physics (JETP),2, 576 (1956);B. Stech:Zeits. f. Phys.,145, 319 (1956);M. Ross:Phys. Rev.,104, 1736 (1956).
SeeJ. Schwinger:Ann. Phys.,2, 407 (1957).
W. Heisenberg:Rev. Mod. Phys.,29, 269 (1957).
C. N. Yang andR. L. Mills:Phys. Rev.,96, 191 (1954).
S. A. Bludman:Phys. Rev.,100, 372 (1955).
Radiative corrections, which effectively lower the ϱ value, are being investigated for μ-decay through an intermediaryb field, in collaboration withH. S. Wong.
S. A. Bludman andM. A. Ruderman:Phys. Rev.,101, 910 (1956).Oneda and collaborators, inNuclear Physics,1, 445 (1956) and earlier papers, obtain a different rate for K → μ + v because, in the interaction (A1), they omit the factorM −1 which is different for π and for K decay.
M. L. Goldberger andS. B. Treiman:Phys. Rev.,110, 1178 (1958).
T. D. Lee andC. N. Yang:Phys. Rev.,108, 1645 (1957).
L. Stevenson:A.P.S. Stanford meeting, 1957.
W. H. Barkas: (UCRL) private communication.
The experimental transition rates into each mode are taken from the survey byM. Gell-Mann andA. H. Rosenfeld, Jr.:Ann. Rev. Nuclear Sci.,7, (1957).
J. J. Sakurai:Phys. Rev.,108, 491 (1957).
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Reported on at theNew York meeting of the American Physical Society, Jan. 29 1957;Bull. Am. Phys. Soc., Ser. II,3, 20 (1958).
This work was done under the auspices of the U.S. Atomic Energy Commission.
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Bludman, S.A. On the universal fermi interaction. Nuovo Cim 9, 433–445 (1958). https://doi.org/10.1007/BF02725099
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DOI: https://doi.org/10.1007/BF02725099