On the Disintegration of Slow Mesons

Abstract

With the same experimental device used in a previous work for a direct determination of the mean life of slow mesons, we have performed some measurements designed to give indications about the disintegration process of the mesons stopped in an iron plate. In agreement with the theoretical predictions of Tomonaga and Araki we found that only about one-half of the ionizing particles that compose the hard component of the cosmic rays and that are absorbed in an iron plate, undergo, in effect, the disintegration process. From the same experimental results, one deduces that the mean range of the decay-electrons is about 2.5 cm of iron, with a probable precision of 20 percent.