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.

70 Years of π-Meson with César Lattes

“…No período 1943−1946, esses italianos realizaram uma série de experimentos em Roma, onde mediram com grande precisão a vida-média dos mésotrons, encontrando (2,33 ± 0,15) microssegundo [25,26], como também estudaram a absorção desses mésotrons na matéria [27,28].…”

The Italian contributions to cosmic-ray physics from Bruno Rossi to the G-Stack. A new window into the inexhaustible wealth of nature

“…Then, in the autumn 1941, two of Bernardini's collaborators, Marcello Conversi and Oreste Piccioni, without knowing about the French experiment, decided to try a "direct" experiment too. Their work, finished in February 1943, was published in Nuovo Cimento [111,112], but it was not published in the Physical Review until 1946 because of the wartime [113,114]. Their experiment, which was "performed by counting delayed coincidences between the impinging low energy mesons and the decay electrons" (cf.…”

“…( 30 ) A few isolated papers were published in some other universities, such as Messina (by Salvatore Patanè and Beltramino Panebianco [118][119][120][121]), Pavia (by Rita Brunetti and Zaira Ollano [122,123]) and Torino (Giuseppe Lovera [124,125]), but no systematic, regular work was carried out in these universities. It shows, in a vertical section, the disposition of the four groups of counters, the lead screens, and the iron absorber (reproduced from [114], p. 875).…”

“…11. -The experimental arrangement of the apparatus designed by Conversi and Piccioni.It shows, in a vertical section, the disposition of the four groups of counters, the lead screens, and the iron absorber (reproduced from[114], p. 875).…”

On the Range of Decay Electrons from Mesons

“…2 The purpose of this note is to point out that an extension of this mathematical method will also give the dynamic interaction energy. Thus the solution \p= (expx)^ where x= l/c*/<&[2Mi**+2, (<f>f v */k-kiAi*f*/k* and…”