Anomalous nuclear enhancements in hard pA collisions at Fermilab energies

Data on pA→ dijet events from Fermilab experiment E609 have been used in a study of anomalous nuclear cross section enhancement effects. The dijet cross section was found to vary as A1.18±0.05, after making a correction for additional non-jet transverse energy in dijet events from heavy nuclei. We have also measured the nuclear contribution to the transverse momentum unbalance of the dijet system to vary as ktφ (nuclear) ≅ A0.11±0.04. The extent to which multiple nuclear scattering of the high energy scattered partons can explain both kt and the observed anomalous enhancement is discussed. (orig.)