Tensor charge of the nucleon in lattice QCD

The first results of lattice QCD simulations on the nucleon tensor charge delta q are presented. From the quenched QCD simulations with the Wilson quark action at beta = 5.7 (the lattice spacing a similar or equal to 0.14 fm) on a 16(3)x20 lattice and on a 12(3)x20 lattice, we find (i) the connected part delta q(con) is determined with small statistical error, (ii) the disconnected part delta q(dis), which violates the OZI rule, is consistent with zero, and (iii) the flavor-singlet tensor charge delta Sigma(mu(2) = 2 GeV2)= delta u + delta d + delta s takes 0.562(88) in the quenched simulation at beta = 5.7 on a 16(3)x20 lattice.