New QCD Sum Rules for Nucleon Tensor Charge

Abstract

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.