Charged Particle Production in Stopped Pion Absorption by Nuclei

• Published in: Physics of atomic nuclei Vol. 82; no. 4; pp. 351 - 357
• Main Authors: Gurov, Yu. B., Karpukhin, V. S., Lapushkin, S. V., Leonova, T. I., Pritula, R. V., Chernyshev, B. A., Sandukovsky, V. G.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-07-2019; Springer; Springer Nature B.V
• Subjects: Absorption; Charged particles; Helium isotopes; Nuclei; Particle and Nuclear Physics; Particle production; Physics; Physics and Astronomy
• ISSN: 1063-7788; 1562-692X
• DOI: 10.1134/S1063778819030074

The spectra of
3,4
He charged particles produced in stopped pion absorption by nuclei were measured for 17 nuclei in the mass-number range of 6 ≤
A
≤ 209 by means of a semiconductor spectrometer. These data were analyzed on the basis of a phenomenological model where the absorption reaction in question is treated as a three-stage process: primary absorption by intranuclear clusters, preequilibrium stage, and evaporation stage. It is shown that a dominant contribution to the production of helium isotopes with energies not less than 20 MeV comes from the preequilibrium stage. The contribution of the knockout and pickup mechanisms to
3,4
He production is estimated.