K-vacancy production by 4.88-GeV protons

Cross sections for $K$-vacancy production by 4.88-GeV protons on elements between Ni and U have been measured. These cross sections lie approximately a factor of 1.4 to 2.5 above the plane-wave Born-approximation predictions. To partially explain these deviations, we argue that an additional contribution due to the interaction between the currents of the projectile and target electrom must be added to these theories.