Mueller–Navelet jets in next-to-leading order BFKL: theory versus experiment

F Caporale,A Papa,B Murdaca,D Yu Ivanov

doi:10.1140/epjc/s10052-014-3084-z

Abstract

We study, within QCD collinear factorization and including BFKL resummation at the next-to-leading order, the production of Mueller–Navelet jets at LHC with center-of-mass energy of 7 TeV. The adopted jet vertices are calculated in the approximation of a small aperture of the jet cone in the pseudorapidity-azimuthal angle plane. We consider several representations of the dijet cross section, differing only beyond the next-to-leading order, to calculate a few observables related with this process. We use various methods of optimization to fix the energy scales entering the perturbative calculation and compare our results with the experimental data from the CMS collaboration.

Highlights

The investigation of jet production in perturbative QCD is an important element of phenomenological studies at LHC
The appearance of the first CMS data at a center-of-mass energy of 7 TeV [40] triggered the theoretical analysis in the same kinematical setup, which showed that the use of a RGimproved kernel with non-optimized energy scales does not lead to agreement with the experiment [41], but nice agreement is found at the larger values of Y when Brodsky–LePage–McKenzie method (BLM)-optimal energy scales are used instead [42], both in pure BFKL and renormalization group (RG)-improved calculations
The paper is organized as follows: we will give the kinematics and the basic formulas for the Mueller–Navelet jet process cross section, present the different, next-to-leading order (NLO)-equivalent representations of the amplitude adopted in this work and briefly recall the principle of minimum sensitivity (PMS), fast apparent convergence (FAC), and BLM optimization methods; in Sect. 3 we will present our results; in Sect. 4 we will draw our conclusions and discuss some issues which we believe to be important in confronting the theoretical predictions with experimental data

Summary

Introduction

The appearance of the first CMS data at a center-of-mass energy of 7 TeV [40] triggered the theoretical analysis in the same kinematical setup, which showed that the use of a RGimproved kernel with non-optimized energy scales does not lead to agreement with the experiment [41], but nice agreement is found at the larger values of Y when BLM-optimal energy scales are used instead [42], both in pure BFKL and RG-improved calculations. The paper is organized as follows: we will give the kinematics and the basic formulas for the Mueller–Navelet jet process cross section, present the different, NLO-equivalent representations of the amplitude adopted in this work and briefly recall the PMS, FAC, and BLM optimization methods; in Sect. The paper is organized as follows: we will give the kinematics and the basic formulas for the Mueller–Navelet jet process cross section, present the different, NLO-equivalent representations of the amplitude adopted in this work and briefly recall the PMS, FAC, and BLM optimization methods; in Sect. 3 we will present our results; in Sect. 4 we will draw our conclusions and discuss some issues which we believe to be important in confronting the theoretical predictions with experimental data

The Mueller–Navelet jet process

Numerical results

Discussion