Production ofJ/ψ via ψ’ and χ decay in 300 GeV/cproton- andπ±-nucleon interactions

The production of the ${\mathrm{\chi }}_1$ and ${\mathrm{\chi }}_2$ states of charmonium has been observed in 300 GeV/c ${\mathrm{\pi }}^{\pm }$N and pN interactions. The fraction of the total inclusive J/ψ production due to radiative χ decay has been determined to be 0.40±0.04, 0.37±0.03, and 0.30±0.04 for the ${\mathrm{\pi }}^{+}$, ${\mathrm{\pi }}^{\mathrm{-}}$, and proton data, respectively. Total cross sections have been obtained of 131±18±14 and 188±30±21 nb/nucleon in the 300 GeV/c ${\mathrm{\pi }}^{\mathrm{-}}$N interactions for ${\mathrm{\chi }}_1$ and ${\mathrm{\chi }}_2$ production. By measuring the contributions to the J/ψ production due to both ψ’ and radiative χ decay, the cross sections for direct J/ψ production have been determined to be 97±14, 102±14, and 89±12 nb/nucleon for ${\mathrm{\pi }}^{+}$, ${\mathrm{\pi }}^{\mathrm{-}}$, and protons, respectively.