Quenching of leading jets and particles: The p⊥ dependent Landau-Pomeranchuk-Migdal effect from nonlinear k⊥ factorization

We report the first derivation of radiative nuclear stopping (the Landau-Pomeranchuk-Migdal effect) for leading jets at fixed values of the transverse momentum p in the beam fragmentation region of hadron-nucleus collisions from Relativistic Heavy Ion Collider (RHIC) to Large Hadron Collider (LHC). The major novelty of this work is a derivation of the missing virtual radiative pQCD correction to these processes—the real-emission radiative corrections are already available in the literature. We manifestly implement the unitarity relation, which in the simplest form requires that upon summing over the virtual and real-emission corrections the total number of scattered quarks must exactly equal unity. For the free-nucleon target, the leading jet spectrum is shown to satisfy the familiar linear Balitsky-Fadin-Kuraev-Lipatov leading log⁡-(1)/(x) (LL(1)/(x)) evolution. For nuclear targets, the nonlinear k_⊥-factorization for the LL-(1)/(x) evolution of the leading jet spectrum is shown to exactly match the equally nonlinear LL(1)/(x) evolution of the collective nuclear glue—there emerges a unique linear k_⊥-factorization relation between the two nonlinear evolving nuclear observables. We argue that within the standard dilute uncorrelated nucleonic gas treatment of heavy nuclei, in the finite energy range from RHIC to LHC, the leading jet spectrum can be evolved in the LL(1)/(x) Balitsky-Kovchegov approximation. We comment on the extension of these results to, and their possible Reggeon field theory interpretation for, midrapidity jets.