The atomic capture and transfer of stopped negative pions have been studied in binary gas mixtures of H2 + M, where M is CCl2F2, CClF3, CBrF3 or SF6. The π0 yield, versus relative atomic concentration CA of M, goes through a maximum at CA ∼ 0.1 and levels off at zero at high concentrations. This phenomenon together with other observed characteristics of the atomic capture and transfer of pions in these systems is interpreted in the frame of a phenomenological model. The average transfer coefficients \ ̄gLZ exhibit a weak concentration dependence. The estimated average atomic capture ratios A ̄( Z H) are lower than those found for noble gases, probably because of the mutual screening of the constituent atoms in the molecules. The probability of pion capture in an atomic orbit is not proportional to the stopping power of the components of the mixture.
- Nuclear Reactions
ASJC Scopus subject areas
- Nuclear and High Energy Physics