A Study of the Two-Meson Hypothesis

Citation

Latter, Richard (1949) A Study of the Two-Meson Hypothesis. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/yypa-vk52. https://resolver.caltech.edu/CaltechTHESIS:06022025-152056180

Abstract

An attempt was made to obtain some indication theoretically as to the tensor character of the heavy and the light me sons observed in cosmic rays. For this purpose the two-meson hypothesis of Bethe and Marshak was accepted. The heavy meson which interacts with nucleons was assumed to be either a scalar, a vector, or a pseudoscalar field in agreement with nuclear force theories. The light meson was assumed to be either a scalar, a pseudoscalar, or a spin ½ field in agreement with the evidence on meson burst production. The associated secondary neutral particle was assumed to have the same tensor character as the light meson. Conservation of spin and statistics limited consideration to seven mixed fields. For each of these fields the decaytime of the heavy meson into the light meson and the lifetime of the light meson for nuclear capture was computed. Using the most recent values of the masses of the heavy and light mesons, the decaytime of the heavy meson is τ(scalar → spin ½)~ 1.22x10^-8sec., τ(pseudoscalar~spin ½)~1.94x10^-9sec., τ(vector~spin ½)~1.88x10^-8sec., t(vector → pseudoscalar or scalar)~6.31x10^-7sec., ~(scalar → pseudoscalar or scalar)~ 1.97x10^-8sec.. These values are to be compared with the experimental value of 10^-8sec. In view of the zero mass of the neutral secondary particle which makes it possible to identify it with a neutrino and the ease of nuclear production of the heavy meson, the indication is that the heavy and light mesons are scalar and spin ½ fields, respectively.

Thesis Files