Neutron Production Of Charm Particles In Fermilab E 400 PDF Download

Results are presented from Fermilab E-400 on the production of charmed baryons and mesons at a mean energy of 640 GeV. We show evidence for the charm-strange baryon, .xi./sub c/, and present our measurements of its mass, width, lifetime, cross section and relative branching fractions, and the A, x/sub f/, p/sub t/, and particle/antiparticle dependence of the state. We show evidence for both the .sigma./sub c//sup 2 +/ and .sigma./sub c/°, and present measurements of three mass differences, .sigma./sub c//sup 2 +/ - sigma./sub c/°, .sigma./sub c/° - lambda./sub c/, and .sigma./sub c//sup 2 +/ - lambda./sub c//sup +/. Measurements of the A dependence and particle/antiparticle ratios for .sigma./sub c/ production are also presented. We show preliminary results on the ratio of two decay modes of the D°, D° .-->. K/sup +/K− and D° .-->. K0anti K0. The latter mode has not been previously observed. 8 refs., 10 figs.