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Fifth force finished?

APR 01, 1965

DOI: 10.1063/1.3047365

Physics Today

Recent experiments involving the decay of $K_{2}^{0}$ mesons indicate that a proposed fifth fundamental force does not appear to exist. The new force had been suggested as an explanation for the discovery by J. H. Christenson and collaborators, that $K_{2}^{0}$ mesons seemed to decay into $π^{+}$ and $π^{-} .$ This decay is forbidden by $CP$ invariance, which requires that in particle interactions, the eigenvalue of the product of the charge conjugation operator, C, and the parity operator, P, remain the same. If $CP$ invariance is violated, this implies that time is not reversible in the interaction, since the product of C, P, and T (the time reversal operator) is believed to be conserved.

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© 1965 American Institute of Physics

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This Content Appeared In

Volume 18, Number 4

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