Heavy quark mass expansion for the operator (Q)over-bar gamma(5)Q and the charm content of eta,eta '

Recently in the context of studies of the intrinsic charm content of the nu cleon and of the eta' meson two groups have arrived at different results fo r the 1/m(3) term of the heavy quark expansion for operator (Q) over bar ga mma(5)Q differing by the factor of six. We show that the form of both resul ts violates certain general principles. Using the expression for the axial anomaly with the finite Pauli-Villars regularization we obtain a new expres sion for the 1/m(3) term of the heavy quark expansion for (Q) over bar gamm a(5)Q. With this new result we obtain an estimate for the constant [GRAPHICS] (C) 1999 Elsevier Science B.V. All rights reserved.