Study of charmed-quark production by antineutrinos

This Letter presents the x and y distributions of events with visible strange particles produced in charged-current nu-barp interactions. It is shown that charmed-particle production via the process nu-bar/sub μ/s-bar→μ+c-bar is required. Using a simple model, we obtain, for the proton, ∫xs-bar(x)dx=0.007 +- 0.002 and ∫xs-bar(x)dx/∫xu(x)dx=0.019 +- 0.006 in the kinematic region 0.05<x< or =0.8 and 0.1<y< or =0.8. Moreover, these observations require a significant left-handed component for the (/sup c//sub s/) doublet