Charge symmetry breaking in spin-dependent parton distributions and the Bjorken sum rule

We present the first determination of charge symmetry violation (CSV) in the spin-dependent parton distribution functions of the nucleon. This is done by determining the first two Mellin moments of the spin-dependent parton distribution functions of the octet baryons from Nf=2+1 lattice simulations. This exploratory work is performed using a single value of the lattice spacing and volume. The results are compared with predictions from quark models of nucleon structure. We discuss the contribution of partonic spin CSV to the Bjorken sum rule, which is important because the CSV contributions represent the only partonic corrections to the Bjorken sum rule.