Diffractive production of Drell–Yan pairs and heavy flavors

Partonic interpretation of high-energy reactions is known to depend on a reference frame. Particularly, in the rest frame of the target Drell–Yan process looks like a freeing of the projectile ll̄ fluctuation, rather than qq̄→ll̄ annihilation. The light-cone representation for Drell–Yan reaction is very similar to that in DIS and exposes a substantial contamination of soft interactions which turns out to be dominant in diffractive production of lepton pairs and in nuclear shadowing. We estimate the fraction of diffractive events in the total Drell–Yan cross section, which scales in M2, and find a substantial deviation from factorization. An analogous approach is developed for diffractive production of heavy flavors.