[en] The influence of resonance production on angular correlations in semi-inclusive π^-p and π^-n interactions at 40 GeV/c are studied. Investigating the correlation variable dsub(ππ)(M) as a function of the two-pion invariant mass, signals for rho⁰ meson production in π^-p and π^-n interactions were observed. Higher values for the azimuthal angle phi between pions produced in the rho⁰ decay are obtained due to the limitation of the resonance transverse momenta. In agreement with the presence of two components in rho⁰ production, positive longitudinal momentum for pions produced in rho⁰ decay are preferentially observed. (author)

[en] A large variety of experimental data on stopped negative pion absorption by nuclei from C to Bi (energy spectra and multiplicities of n, p, d, t, ³ He, and ⁴ He ; angular correlations of two secondary particles; spectra of the energy release in the 'live' ²⁸ Si target on recording protons, deuterons and tritons in the energy range 40-70 MeV, 30-60 MeV and 30-50 MeV, respectively; isotope yields; momentum and angular momentum of residual nuclei) are analysed within the framework of the cascade-exciton model of nuclear reaction. Comparison is made with other up-to-date models of the process. The contributions of different pion absorption mechanisms and the relative role of different particle production mechanisms in this reactions are discussed. (Author)

No abstract available

[en] Short communication

[en] Double-scattering effects are studied in π^-d interactions at 360 GeV/c. The partial cross sections sigmasub(N) (π^-d), sigmasub(N) ('π^-p') and sigmasub(N) ('π^-n') are presented. The double-scattering probability per πd collision is found to be f = 0.15 +- 0.02. The partial cross section Xsub(N) of the double-scattering plus interference contributions is extracted and it is found that Xsub(N) obeys KNO scaling. The data are compared with various theoretical predictions. (Auth.)

[en] Measurements of πN/sub up-arrow/→π⁺π^-N reaction on polarized target at 6, 12 and 17.2 GeV/c provide evidence for a new resonant state 0⁺⁺(750) with a π⁺π^- decay width of 100 MeV or less. The o⁺⁺(750) meason is best understood as the lowest mass gluonium state 0⁺⁺(gg)

[en] The proton screening correction deltasub(p) in a deuteron has been measured by comparative investigation of reactions π^-d→π⁺X^- and π^-p→π⁺X^- at p₀=2.6 GeV/c and psub(T)² approximately=0.0025+-0.0025 (GeV/c)². In the region under investigation the reaction π^-n→π⁺ X^-- is kinematically forbidden. On the basis of the value deltasub(p)=0.177+-0.019 the Glauber parameter was found to be < r^-2>=0.37+-0.05 fm^-2. (Auth.)

[en] The inclusive γ production process π⁺p → γ + anything has been studied at an incident momentum of 16 GeV/c. The experimental results for γ's have been used to determine the average π⁰ multiplicities and the cross sections for π⁰ production. An indirect method was used for the π⁰ momentum distribution. The Mueller correlation parameters f₂(π^-, π⁰) and f₂(π⁰, π⁰) have been determined. (orig.)

[en] Distributions of neutron momenta (psub(n)>=1 GeV/c) have been obtained in π^-p-, π^-n- and π^-₁₂C-interactions at 40 GeV/c by means of studying secondary neutral stars induced by neutrons in 2m propane bubble chamber. The following values of the mean neutron momenta have been obtained: < psub(n)>=2,2+-0.1; 1.7+-0.2; 1.7+-0.1 GeV/c in above mentioned reactions. The average numbers of neutrons have also been estimated: < Nsub(n)(πsup(-)p)>=0.37+-0.04; < Nsub(n)(πsup(-)n)>=0.63+-0.07 and < Nsub(n)(πsup(-) sup(12)C)>=1.32+-0.06

[en] Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (π,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs