Impact parameter dependent parton distributions and off-forward parton distributions for ζ→0

Matthias Burkardt
2000 Physical Review D, Particles and fields  
It is shown that off-forward parton distributions for ζ =0, i.e. where the initial and final state differ only in their transverse momenta, can be interpreted as a simultaneous measurement of the longitudinal momentum and transverse position (impact parameter) of partons in the infinite momentum frame.
doi:10.1103/physrevd.62.071503 fatcat:jjp6o5xz3zebbptguby2ubki5m