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Longitudinal Polarization of the Positrons from the Decay of Unpolarized Positive Muons


IT is now well known that parity is not conserved in weak Fermi interactions, and that this generally results in longitudinal polarization of the spins of the emitted particles. Very strong polarizations of the muons emitted in pion decay1, and of the electrons emitted in beta decay2, have already been detected. The experiment reported here was aimed at detecting longitudinal polarization of the positrons emitted in the decay of unpolarized muons.

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  1. Garwin, R. L., Lederman, L. M., and Weinrich, M., Phys. Rev., 105, 1415 (1957). Cassels, J. M., O'Keeffe, T. W., Rigby, M., Wetherell, H. M., and Wormald, J. R., Proc. Phys. Soc., A, 70, 543 (1957). Friedman, J. I., and Telegdi, V. L., Phys. Rev., 106, 1290 (1957). Alston, M. H., Evans, W. H., Morgan, T. D. N., Newport, R. W., Williams, P. R., and Kirk, A., Phil. Mag., 2, 1143 (1957).

    Article  ADS  CAS  Google Scholar 

  2. Frauenfelder, H., Bobone, R., Goeler, E. von, Levine, N., Lewis, H. R., Peacock, R. N., Rossi, A., and Pasquali, G. de, Phys. Rev., 106, 386 (1957). Cavanagh, P. E., Turner, J. F., Coleman, C. F., Gard, G. A., and Ridley, B. W., Phil. Mag., 2, 1105 (1957).

    Article  ADS  CAS  Google Scholar 

  3. Lee, T. D., Proc. 7th Rochester Conf. 1957 (Interscience Pub., Inc.).

  4. Goldhaber, M., Grodzins, L., and Sunyar, A. W., Phys. Rev. 106. 826 (1957).

    Article  ADS  CAS  Google Scholar 

  5. Lederman, L. M., Proc. 7th Rochester Conf., 1957 (Interscience Pub., Inc.).

  6. McVoy, K. W., and Dyson, F. J., Phys. Rev., 106, 1360 (1957).

    Article  ADS  CAS  Google Scholar 

  7. Gunst, S. B., and Page, L. A., Phys. Rev., 92, 970 (1953).

    Article  ADS  CAS  Google Scholar 

  8. Herrmannsfeldt, W. B., Maxson, D. R., Stahelin, P., and Allen, J. S., Phys. Rev., 107, 641 (1957).

    Article  ADS  CAS  Google Scholar 

  9. Stapp, H. P., Phys. Rev., 107, 634 (1957).

    Article  ADS  CAS  Google Scholar 

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CULLIGAN, G., FRANK, S., HOLT, J. et al. Longitudinal Polarization of the Positrons from the Decay of Unpolarized Positive Muons. Nature 180, 751–752 (1957).

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