Fig.(1) The real (upper panels) and imaginary (lower pannels) parts of the spacelike H (ξ) (1^st and 2^nd columns) and timelike H (η) (3^rd and 4^th columns) Compton Form Factor multiplied by ξ (or η ), in the double distribution model based on GK (1^st and 3^rd columns) and MSTW08 (2nd and 4th columns) parametrizations, for µ_F² =Q² = 4GeV² and t = −0.1GeV² . In all plots, the LO result is shown as the dotted line, the full NLO result by the solid line and the NLO result without the gluonic contribution as the dashed line.