During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy. In total about 100 000 charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. A high-statistics sample of neutrino interactions with a D 0 in the final state was collected. Using the decay mode D * + → D 0 π + a production cross-section measurement of the D * + in neutrino–nucleon charged-current interactions was performed. The low Q-value of the decay was used to isolate a sample of candidate events containing a positive hadron with a small p T with respect to the D 0 direction. A signal of 22.1 ± 5.5 D * + events was obtained. The D * + production cross-section relative to the D 0 production cross-section, σ ( D * + ) / σ ( D 0 ) , was estimated to be 0.38 ± 0.09 ( stat ) ± 0.05 ( syst ) . From this result, the fraction of D 0 's produced via the decay of a D * was deduced to be 0.63 ± 0.17 . The D * + production cross-section relative to the ν μ charged-current interaction, σ ( D * + ) / σ ( CC ) , was estimated to be [ 1.02 ± 0.25 ( stat ) ± 0.15 ( syst ) ] % .
