  The ratio of B+ and B0 meson lifetimes was measured using data collected in
2002-2004 by the D0 experiment in Run II of the Fermilab Tevatron Collider.
These mesons were reconstructed in B -> mu+ nu D*- X decays, which are
dominated by B0, and B ->mu+ nu D0bar X decays, which are dominated by B+. The
ratio of lifetimes is measured to be t+/t0 = 1.080 +- 0.016(stat) +-
0.014(syst).
