Fig.(3) The DVCS observables for the COMPASS experiment, from left to right, mixed charge-spin asymmetry, mixed charge-spin difference and mixed charge-spin sum (in nb/GeV⁴). The kinematical point is chosen as ξ = 0.05, Q² = 4 GeV², t = −0.2 GeV². The GPD H(x,ξ ,t ) is parametrized in the double distribution model based on the MSTW08 parametrization. The contributions from other GPDs are not included.