# Tracking fast small color dipoles through strong gluon fields at the LHC - High Energy Physics - Phenomenology

Abstract: We argue that the process gamma +A \to J-psi + gap + X at large momentumtransfer provides a quick and effective way to test onset of a novelperturbative QCD regime of strong absorption for the interaction of smalldipoles at the collider energies. We find that already the first heavy ion runat the LHC will allow to study this reaction with sufficient statistics viaultraperipheral collisions hence probing the interaction of q\bar q dipoles ofsizes ~ 0.2 fm with nuclear media down to x ~ 10^{-5}.

Author: L.Frankfurt TAU, M.Strikman PSU, M.Zhalov PNPI

Source: https://arxiv.org/