Target mass corrections for spin-dependent structure functions in   collinear factorization
  We derive target mass corrections (TMC) for the spin-dependent nucleon structure function g1 and polarization asymmetry A1 in collinear factorization at leading twist. The TMCs are found to be significant for g1 at large xB, even at relatively high Q^2 values, but largely cancel in A1. A comparison of TMCs obtained from collinear factorization and from the operator product expansion shows that at low Q^2 the corrections drive the proton A1 in opposite directions. 
A. Accardi, W. Melnitchouk