Limits for four- and five-prong semimuonic charm meson decays

Upper limits at the 90% confidence level are presented for four- and five-prong semimuonic decays of charm mesons. From a study of four-prong vertices we find B(D0 → K−π+π−μ+ν)/B(D0 → K−μ+ν) < 0.037 and B (D0 → (K∗ (892)π)−μ+ν)/B(D0 → K−μ+ν) < 0.043. The five-prong vertices yield the result B(DS+ → η′μ+ν) / B(DS+ → φμ+ν) < 1.6.