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 ..mu../s-bar..--> mu../sup +/c-bar is required. Using a simple model, we obtain, for the proton, ..integral..xs-bar(x)dx=0.007 +- 0.002 and ..integral..xs-bar(x)dx/..integral..xu(x)dx=0.019 +- 0.006 in the kinematic region 0.05