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U(12) and Time-Reversal Asymmetry in the Weak Interactions

Zachariasen, F. and Zweig, G. (1965) U(12) and Time-Reversal Asymmetry in the Weak Interactions. Physical Review Letters, 14 (19). pp. 794-798. ISSN 0031-9007. doi:10.1103/PhysRevLett.14.794.

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Experimental studies of leptonic decays leave little doubt that the leptons ℓ enter the WI only through the combination jµℓ = µ[bar]γµ(1 +i γ5)vℓ. Theoretical arguments have been presented which make such a world quite "natural." Feynman and Gell-Mann [4], for example, assume that the most "fundamental" description of a fermion is given by a two-component object which satisfies a second-order differential equation. They further assume that it is precisely this two-component spinor that enters the WI, thereby obtaining the V-A theory. Feynman and Gell-Mann argue in this manner not only for leptons, but also for the "bare" hadrons (strongly interacting particles). This exclusion of scalar (s), pseudoscalar (p), and tensor (t) pieces from the hadronic part of the WI has not been experimentally verified. In fact, the argument against s, p, and t in nonleptonic decays rests solely in our belief that there exist "fundamental" or "bare" hadrons. While leptons may be "fundamental," we have every reason to believe that hadrons are not. Consequently, we postulate (i) the existence of s, p, and t in addition to the conventional v, a terms in the hadronic part of the WI; the leptonic piece remains the same.

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Additional Information:©1965 The American Physical Society. Received 25 January 1965 We should like to thank Dr. Roger Dashen and Dr. Yuval Ne'eman for a number of interesting and valuable conversations. Work supported in part by the U.S. Atomic Energy Commission. Prepared under Contract No. AT(11-1)-68 for the San Francisco Operations Office, U.S. Atomic Energy Commission.
Issue or Number:19
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6270
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Deposited On:30 Nov 2006
Last Modified:08 Nov 2021 20:32

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