摘要: Fermilab E769, a fixed-target experiment conducted during the 1987--88 running period, yielded large numbers of charm particles. Through collisions of 250 GeV (pi)(sup (+-)), K(sup (+-)), and p on a multifoil target, E769 allows f... 展开 Fermilab E769, a fixed-target experiment conducted during the 1987--88 running period, yielded large numbers of charm particles. Through collisions of 250 GeV (pi)(sup (+-)), K(sup (+-)), and p on a multifoil target, E769 allows for studies of beam flavor dependence in the hadroproduction of charm. Through the decay modes D(sup +) (yields) K(sup (minus))(pi)(sup +)(pi)(sup +), D(sub s)(sup +) (yields) (phi)(pi)(sup +), and D(sub s)(sup +) (yields) (anti K)(sup *0) K(sup +) (and charge conjugates), the authors have extracted D(sup (+-)) and D(sub s)(sup (+-)) signals for all five beam types. They report preliminary measurements of the beam dependence of the absolute production cross-sections (For Feynman x > 0) of the D(sup (+-)) and D(sub s)(sup (+-)). 收起