The Heavy Quark Expansion for the Charm Quark

Abstract

We show that one can re-arrange the Heavy Quark Expansion for inclusive weak decays of charmed hadrons in such a way that the resulting expansion is an expansion in ${\Lambda }_{\mathrm{QCD}}/m_c$ and ${\alpha }_s(m_c)$ with order-one coefficients. Unlike in the case of the bottom quark, the leading term includes not only the contribution of the free-quark decay, but also a tower of terms related to matrix elements of four quark operators.

4 pages