Summary
If the electron and its associated neutrino v and the muon and its associated neutrino u are put into two isodoublets, then a strangeness-conserving isovector weak 4-currentJ λ can be defined such that weak interaction ∞J λ·J λ conserves isospin. The « neutral currents » so introduced do not affect the rates of Β-decay, Μ-capture, etc., predict no « unwanted processes» (e.g., Μ+p→e+p), and in fact predict only weak scattering. A choice between this « symmetric » theory and the present « charged current» theory may be made by looking for « Class Β» scattering, such as e+u→ e+u, for which the present theory gives zero cross-sections but our symmetric theory predicts cross-sections of the same order as e-v scattering on the present theory.
Riassunto
Se si pongono in due isodoppietti l’elettrone con il neutrino v ad esso associato ed il muone con il neutrino u ad esso associato, si puó definire una quadricorrente vettoriale che conserva la stranezza,J λ, tale che l’interazione debole ∞J λ·J λ conserva l’isospin. Le « correnti neutre » cosi introdotte non influiscono sui rapporti del decadimento Β, della cattura Μ, ecc, non predicono «processi indesiderabili » (p. es. Μ+p→ e+p), ed in effetti predicano solo scattering deboli. Si puÒ effettuare una scelta fra questa teoria « simmetrica » e l’attuale teoria della « corrente carica » ricercando lo scattering di «classe Β », come e+Μ→e+Μ, per cui la teoria attuale dà una sezione d’urto nulla, mentre la nostra teoria simmetrica predice sezioni d’urto dello stesso ordine dello scattering e-v ottenute con la teoria attuale.
Similar content being viewed by others
References
G. Danby, J.-M. Gaillard, K. Goulianos, L. M. Lederman, N. Mistry, M. Schwartz andJ. Steinberg:Phys. Rev. Lett.,9, 36 (1962).
See for exampleO. Klein:Ark. f. Fys.,16, 191 (1959); A. Gamba, R. Marshak and S. Okubo:Proc. Nat. Acad. Sei.,45, 881 (1959); W. Królikowski:Nuovo Cimento,24, 52 (1962).
See, for example,R. Marshak andE. C. G. Sudarshan:Introduction to Elementary Particle Physics (New York, 1961), Chap. 5, Section 5.
Our metric is g11= g22=g33 = -g44= + 1. In general our notation and the cross-section calculations of Section 3 will follow as closely as possible those ofJ. Jauch andP. Eohelich:The Theory of Photons and Electrons (Cambridge, 1955).
Cf.M. Gell-Mann:Phys. Rev.,125, 1067 (1962), eqs. (1.1) and (1.2) (the prefixed minus sign in eq. (1.6) is irrelevant).
Ref. (5), Chap. 5, eq. (73).
Ref. (5), Chap. 5, eq. (75).
See, for example,J. Nilsson:Nuovo Cimento,23, 1102 (1962).
E. Feynman:Theory of Fundamental Processes (New York, 1961), p. 164.
See also the general theory ofR. Finkelstein andW. Ramsat:Ann. of Phys.,21, 408 (1963).
Author information
Authors and Affiliations
Additional information
Acknowledging the support of the National Science Foundation and the Argonne National Laboratory.
Rights and permissions
About this article
Cite this article
Ingraham, R.L., Melvin, M.A. Lepton isodoublets. Nuovo Cim 29, 1034–1042 (1963). https://doi.org/10.1007/BF02750129
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02750129