Extracting the pion distribution amplitude from correlation functions in position space
We determine the pion distribution amplitude from three-point functions, where two currents are at the same time with a space-like separation. Having control over the discretization effects turned out to be mandatory. This can be achieved by the choice of suitable channels and by taking into account discretization effects to leading order in the strong coupling. Furthermore, it is necessary to have fairly high pion momenta to be sensitive to deviations of the DA from its asymptotic shape. To that end we apply the novel momentum smearing technique.
Preferred track (if multiple tracks have been selected)