Study of the decay B. -->. psiX

We have measured the inclusive branching ratio for B..-->..psiX to be (1.09 +- 0.16 +- 0.21)%, and the exclusive branching ratios for B/sup -/..-->..psiK/sup -/ and B-bar /sup 0/..-->..psiK-bar /sup *//sup 0/ to be (0.09 +- 0.05)% and (0.41 +- 0.18)%, respectively. The mass difference between neutral and charged B mesons is 1.1 +- 2.1 MeV, while the difference between the mass of UPSILON(4S) and twice the mean B-meson mass is 18.5 +- 3.0 MeV. The psi momentum distribution implies a substantial two-body decay (in agreement with direct measurements), but also some combination of B..-->..psiX with M/sub X/>1.5 GeV, and B..-->..psi'X.