[en] The inclusive semileptonic decay B→X_clν yields the best extracted value of vertical stroke V_cb vertical stroke with an uncertainty of about 2%, which is due to its precise theoretical description by the heavy-quark expansion (HQE) and the large amount of data collected by the B factories Babar and Belle. Besides the precision determination of vertical stroke V_cb vertical stroke and the HQE parameter it also enables us to test for new physics effects. Normal decays with a small standard model contribution are investigated on the quest for new physics, like flavour-changing neutral currents, which are suppressed in the standard model by the GIM mechanism. But as right-handed weak currents are absent in the standard model their appearance would be a smoking gun signal for new physics in the decay considered here. We perform such an analysis, which is known form the leptonic sector as ''Michel parameter analysis''. Contributions from possible new physics effects are derived with effective field theory methods, yielding an enhanced b → c current, with not only a right-handed vector contribution, but also scalar and tensor couplings. We repeat the computations of the decay with the enhanced current up to O(1/m_b²) in the HQE and up to O(α_s) in the perturbative corrections. A moment analysis of the moments of the lepton energy spectrum and the hadronic invariant mass has become a reliable tool in both the theoretical evaluation and the experimental determination. This combines in a HQE fit, which has been improved frequently, yielding a precise determination of the HQE parameters and especially the best extracted value for vertical stroke V_cb vertical stroke. The HQE fit may as well serve as a test for new physics effects in these moments. The theoretical analysis of the moments reveals a low sensitivity of the moments on the non-vector currents. Thus we perform the fit with only a possible right-handed vector current contribution. The experience in both, the HQE and the perturbative expansion enables us to consider the radiative corrections to the HQE parameters μ_π² and μ_G², which are a missing puzzle piece in the precise determination of the decay B→X_clν. The determination of the perturbative correction to μ_π² can be easily done via reparametrization invariance, which we present in this work. Unfortunately, the O(α_s) corrections to μ_G² can only be obtained by a full calculation. We present briefly the strategy for such a calculation and give the result for a certain moment of the partonic invariant mass, which can be obtained by only the real corrections, which have been done. (orig.)