Multiplicity of charged particles produced in collisions of π- and K- mesons with nuclei in a streamer chamber at 40 GeV/c

Results are presented on the multiplicities of charged particles of various signs produced in interactions of π- and K mesons with Li, C, S, Cu, Cs(I) and Pb nuclei (range of mass numbers A from 7 to 207). The average multiplicity of negatively charged particles in hadron-nucleon interactions, normalized to the average multiplicity of negatively charged particles in hadron-nucleon interactions, R- = /sub h/A/ /sub h/N, is approximated by the relation R- = (0.78 +- 0.06) +(0.32 +- 0.04)nu-bar. On the contrary, the normalized average multiplicity of all charged particles, R/sup ch/ = /sub h/A//sub h/N, is approximated by a relation with a much larger slope: R/sup ch/ = (0.18 +- 0.10)+(0.85 +- 0.06)nu-bar. Here nu-bar = Asigma/sub h/N/sigma/sub h/A is a quantity usually interpreted as the average number of inelastic collisions of the hadron in the nucleus. Comparison of the multiplicities of fast (with momentum exceeding 0.5 GeV/c) positively and negatively charged particles reveals an excess of positively charged particles, which increases with increasing A. The ratio of the standard deviation to the average multiplicity is practically independent of A in the multiplicity distributions of the negatively charged particles