The Chiral Odd Nucleon Tensor Charge

The subject of the nucleon’s spin composition has been intensely studied and has produced important and surprising insights, beginning with the revelation that the majority of its spin is carried by quark and gluonic orbital angular momenta and gluon spin rather than by quark helicity. In addition, considerable effort has gone into understanding, predicting and measuring the transversity distribution, h1(x), of the nucleon. 3 Transversity, as combinations of helicity states, |⊥/⊤ >∼ ( |+ > ±|− > ), for the moving nucleon is a variable introduced originally by Moravcsik and Goldstein to reveal an underlying simplicity in nucleon–nucleon spin dependent scattering amplitudes. In their analysis of the chiral odd distributions, Jaffe and Ji related the first moment of the transversity distribution to the flavor contributions of the nucleon tensor charge: