Forward dijets in high-energy collisions: evolution of QCD n-point functions beyond the dipole approximation

Abstract

Present knowledge of QCD n-point functions of Wilson lines at high energies is rather limited. In practical applications, it is therefore customary to factorize higher n-point functions into products of two-point functions (dipoles) which satisfy the BK evolution equation. We employ the JIMWLK formalism to derive explicit evolution equations for the 4- and 6-point functions of fundamental Wilson lines and show that if the Gaussian approximation is carried out before the rapidity evolution step is taken, then many leading order N_c contributions are missed. Our evolution equations could specifically be used to improve calculations of forward dijet angular correlations, recently measured by the STAR collaboration in deuteron-gold collisions at the RHIC collider. Forward dijets in proton-proton collisions at the LHC probe QCD evolution at even smaller light-cone momentum fractions. Such correlations may provide insight into genuine differences between the JIMWLK and BK approaches.

8 pages, 1 figure

References in corpus (4)

• Forward inclusive dijet production and azimuthal correlations in pA collisions
• Azimuthal correlations of forward di-hadrons in d+Au collisions at RHIC in the Color Glass Condensate
• Light projectile scattering off the Color Glass Condensate
• Energy losses in the black disc regime and correlation effects in the STAR forward pion production in dAu collisions

Cited by in corpus (2)

• Universality of Unintegrated Gluon Distributions at small x
• Two-gluon correlations and initial conditions for small-x evolution