  Two new QCD sum rules for nucleon tensor charge are derived from a mixed
correlator of spin-1/2 and spin-3/2 nucleon interpolating fields. These sum
rules are analyzed along with a sum rule obtained from the usual correlator of
a general spin-1/2 nucleon interpolating field. The validity and reliability of
the sum rules are examined by monitoring the contaminations arising from the
transitions and continuum and the convergence of the operator product
expansion. Valid sum rules are identified and their predictions are presented.
It is found that the vacuum tensor susceptibility induced by the external field
plays an important role in determining both the validity and predictions of the
sum rules. The uncertainties associated with the sum-rule predictions are also
discussed.
