  We present a calculation of subleading 1/m_b corrections to spectator effects
in the ratios of beauty hadron lifetimes in heavy-quark expansion. We find that
these effects are sizable and should be taken into account in systematic
analyses of heavy hadron lifetimes. In particular, the inclusion of 1/m_b
corrections brings into agreement the theoretical predictions and experimental
observations of the ratio of lifetimes of \Lambda_b-baryon and B_d meson. We
obtain \tau(B_u)/\tau(B_d) = 1.06 \pm 0.02, \tau(B_s)/\tau(B_d)= 1.00 \pm 0.01,
\tau(\Lambda_b)/\tau(B_d)= 0.86 \pm 0.05.

High Energy Physics - Phenomenology;High Energy Physics - Experiment