Nuclear Capture of µ-Mesons

Abstract

IT is well known from delayed-coincidence experiments¹ that negative µ -mesons (mass 215) stopping in light atoms undergo electron decay, whereas those stopping in substances of high atomic number undergo nuclear capture. Both photographic plate^2,3 and cloud-chamber evidence^4,5 shows that very few or none of the µ-mesons produce nuclear disintegration stars in heavy elements. Counter-work⁶ precludes production of photons, though there is evidence for emission of neutrons following meson capture^7,8. It is of interest to discuss the above evidence in the light of observations on µ -mesons stopping in nuclear emulsions.