The effect of NLO conformal spins in azimuthal angle decorrelation of jet pairs

TL;DR

The paper addresses azimuthal angle decorrelation of Mueller–Navelet jet pairs in the Regge limit of QCD and seeks to incorporate next-to-leading corrections to the BFKL kernel. It develops a spectral representation including conformal spins and angular dependence, extending the Ivanov–Papo formalism, and computes the angular differential cross section with running-coupling effects. The results show that NLL corrections substantially tame the energy growth and dramatically reduce the decorrelation between jets, especially via the $n=0$ sector, with higher conformal spins providing additional structure. The work lays groundwork for more complete phenomenology by planning to add NLO jet vertices, parton distributions, and collinearly improved kernels for LHC predictions.

Abstract

Azimuthal angle decorrelation in inclusive dijet cross sections is studied analytically to take into account the next-to-leading corrections to the BFKL kernel while keeping the jet vertices at leading order. The spectral representation on the basis of leading order eigenfunctions is generalized to include the dependence on conformal spins. With this procedure running coupling effects and angular dependences are both included. It is shown how the angular decorrelation for jets with a wide relative separation in rapidity largely decreases at this higher order in the resummation.

Figures (7)

• Figure 1: Evolution in Y of the ${\cal C}_0 ({\rm Y})$ coefficient.
• Figure 2: Evolution of the partonic cross section with the rapidity separation of the dijets.
• Figure 3: Intercepts for the cross section as a function of rapidity.
• Figure 4: Evolution in Y of the ${\cal C}_n ({\rm Y})$ coefficients for $n=1,2,3$.
• Figure 5: Dijet azimuthal angle decorrelation as a function of their separation in rapidity.