D meson lifetimes within the Heavy Quark Expansion

Even if new data indicates that direct CP violation in D meson decays is compatible with the standard model expectation, it triggered a lot of interest and charm phenomenology will remain an essential part of new physics searches due to the unique role as a probe for FCNC among up-type quarks. Charm physics poses considerable theoretical challenges, because the charm mass is neither light nor truly heavy. The Heavy Quark Expansion (HQE) provides a perturbative expansion in the inverse heavy quark mass for inclusive rates. It proved to be very successful in the B sector, yet its validity for charm decays has often been questioned. We present results of a HQE study of D meson lifetimes including NLO QCD and subleading 1/m_c corrections. We find good agreement with experimental data, however with huge hadronic uncertainties due to missing lattice input for hadronic matrix elements.