NEUTRAL STRANGE PARTICLE PRODUCTION IN HIGH ENERGY CHARGED CURRENT NEUTRINO DEUTERIUM INTERACTIONS

In an exposure of the Fermilab 15-foot deuterium filled bubble chamber to a single horn focused wide band neutrino beam with energies between 10 and 250 GeV, 311 K(,s)('(DEGREES)), 219 (LAMDA), and 7(' )(LAMDA) are observed. These correspond to(' )K(DEGREES)(K(DEGREES)), (LAMDA)((SIGMA)(DEGREES)) and(' )(LAMDA) production rates per charged current interaction of 0.170 (+OR-) 0.010, 0.060 (+OR-) 0.004, and 0.002 (+OR-) 0.001, respectively, in 18.9 (+OR-) 0.9% V(DEGREES) events of total charged current events. The inclusive (LAMDA) rate in (nu)n interactions is significantly higher than that in (nu)p interactions. The multiplicity of K(DEGREES) increases (or decreases) with increasing E(,(nu)), W, and Q('2) (or x(,B)), while that of (LAMDA) shows no significant variations. From a detailed study of (LAMDA), (LAMDA)K(DEGREES), (LAMDA)K*('+) systems, the production rate of (LAMDA) from the charm quark decay is found to be (2.1 (+OR-) 1.0)% of the total charged current, which leads to a small cross section for charmed baryon quasielastic production < 5 x 10('-40) cm('2) (90% CL) and a small semileptonic branching ratio of (LAMDA)(,c)('+) decay, B((LAMDA)(,c)('+) (--->) e('+)(LAMDA)x) < 6% (95% CL). The (LAMDA)(pi)('+),(' )K(DEGREES)p, (LAMDA)(pi)('+)(pi)('+)(pi)('-), and(' )K(DEGREES)p(pi)('+)(pi)('-) decay modes of (LAMDA)(,c)('+) are studied and found consistent with our previous results. The existence of the charm production mechanism is confirmed from a study of the inclusive (LAMDA) and (LAMDA)K(DEGREES) rates and x(,B) distributions of the V(DEGREES) events. The gross probability that an (ss) pair is produced in (DELTA)S = 0 neutrino reactions is estimated to be 0.19 (+OR-) 0.06, which agrees well with that in hadronic experiments. The inclusive x(,F)('*) and p(,T)('2) distributions and their average values are very similar to those in hadronic experiments, which suggest that the majority of neutral strange particles are produced in neutrino reactions via the associated production mechanism. The z distributions are found to be the same as in other lepton-nucleon experiments. Finally, from a study of exclusive reactions in a restricted sample, three good examples of (nu)n (--->) (mu)('-)(LAMDA)(,c)('+)((--->) (LAMDA)(pi)('+)) have been observed, and little energy dependence of (sigma)((nu)n (--->) (mu)('-)(LAMDA)K('+)) has been observed with an average value (5.5 (+OR-) 1.3) x 10('-40) cm('2).