Decay constants of pseudoscalar mesons containing heavy quarks

The quantum chromodynamics sum-rules of Shifman, et al., for n-th order moments are applied to the determination of the decay constants of pseudoscalar mesons containing a heavy quark (c or b). The general case when Q(2), the squared momentum transfer, is nonzero is considered. The stability of the sum rules against variations in both Q(2) and n is discussed.