pA collisions
Modified (nuclear) PDFs:
- Parton distributions in nuclei (EKS, BQV) different compared to those of hadrons beyond a simple A-scaling: S(x,Q2,A) = FiA (x,Q2) / [A FiN (x,Q2)]
- Shadowing. S < 1 at small x < 0.07 (parton fusion at small-x)
- Antishadowing: S > 1 peak at x = 0.15 (
- EMC effect: S < 1 again for large x
- Cronin (enhancement) effect: Additional kT “kick” (kT broadening) added to F(x,Q2) to account for multiple initial-state (soft and semi-hard) parton scattering (Wang, Lévai ...) .
- Scale-dependence of nuclear PDFs less known than in the nucleon case (limited range of x and Q2 covered in eA exp.).
- Quark and gluon modifications are different ...