Target mass corrections for spin-dependent structure functions in collinear factorization

We derive target mass corrections (TMC) for the spin-dependent nucleon structure function g1g1 and polarization asymmetry A1A1 in collinear factorization at leading twist. The TMCs are found to be significant for g1g1 at large xBxB, even at relatively high Q2Q2 values, but largely cancel in A1A1. A comparison of TMCs obtained from collinear factorization and from the operator product expansion shows that at low Q2Q2 the corrections drive the proton A1A1 in opposite directions.