Nonperturbative QCD contributions to the inclusive semileptonic decay of the B meson consist of the dynamic and kinematic components. We calculate the decay width in an approach based on the light-cone expansion and the heavy quark effective theory, which is able to include both components of nonperturbative QCD contributions in an almost model-independent way. The kinematic component results in the phase-space extension and is shown to be quantitatively crucial, which could increase the decay width significantly. We find that the semileptonic decay width is enhanced by long-distance strong interactions. This analysis is used to determine the CKM matrix element |V_{cb}| with a controlled theoretical error.
展开▼
