A dynamical approach to semi-inclusive B decays

Semi-leptonic and radiative semi-inclusive decays of heavy mesons are currently under intense investigation. Non perturbative physics seems to be more manageable in such decays, and there is hope for a reduction of theoretical assumptions and a more stringent comparison with experimental data. Several effective approaches to such decays are available. Most commonly, in order to calculate the decay rate, a series of operators is used, whose coefficients and matrix elements are weighted differently according to the theoretical assumptions. The matrix elements of the operators are not calculable within perturbation theory; the largest is the number of operators included in the calculation, the more accurate is the result. Another possible approach is based on an effective strong coupling, in turn based on perturbative threshold resumming and analyticity principles. [1, 2, 3, 4, 5, 6] In such approach, an effective strong coupling is introduced and used in the resummation soft–gluon formulas.