Tensor charge of the nucleon in lattice QCD

The first results of lattice QCD simulations on the nucleon tensor charge δq are presented. From the quenched QCD simulations with the Wilson quark action at β=5.7 (the lattice spacing a0.14 fm) on a 16³×20 lattice and on a 12³×20 lattice, we find (i) the connected part δqcon is determined with small statistical error, (ii) the disconnected part δqdis, which violates the OZI rule, is consistent with zero, and (iii) the flavor-singlet tensor charge δΣ(μ²=2 GeV²)=δu+δd+δs takes 0.562(88) in the quenched simulation at β=5.7 on a 16³×20 lattice.