Non-Spectator Contributions to Inclusive Charmless $B$ Decays

The light quarks inside $B$ mesons are usually treated as spectators and do not affect the decay rates which are assumed to be purely due to b quark decays. In this paper we calculate the non-spectator contributions to inclusive charmless $B$ decays due to the spectator effects. We find that the non-spectator contributions to the branching ratio for $\bar B^0$ are small ($<2\times 10^{-4}$), but the contributions to $\Delta S = 0$ and $\Delta S = -1$, $B^-$ decay branching ratios can be as large as $-7.5\times 10^{-4}$ and $2\times 10^{-3}$, respectively. These contributions may play an important role in rare charmless $B$ decays.