Higher twist contributions to the structure functions F2p(x, Q2) and F2d(x, Q2) at large x at higher orders

The higher twist contributions to the deeply inelastic structure functions F-2(p)(x, Q(2)) and F-2(d)(x, Q(2)) for larger values of the Bjorken variable x are extracted extrapolating the twist-2 contributions measured in the large W-2 region to the region 4 GeV2 <= W-2 <= 12.5 GeV2 applying target mass corrections. We compare the results for the NLO, NNLO and (NLO)-L-3 analyzes and include also the large x at (NLO)-L-4 to the Wilson coefficients. A gradual lowering of the higher twist contributions going from NLO to (NLO)-L-4 is observed, which stresses the importance of higher order corrections. (C) 2008 Elsevier B.V. All rights reserved.