CGC factorization for forward particle production in proton-nucleus collisions at next-to-leading order

Abstract

Within the Color Glass Condensate effective theory, we reconsider the next-to-leading order (NLO) calculation of the single inclusive particle production at forward rapidities in proton-nucleus collisions at high energy. Focusing on quark production for definiteness, we establish a new factorization scheme, perturbatively correct through NLO, in which there is no `rapidity subtraction'. That is, the NLO correction to the impact factor is not explicitly separated from the high-energy evolution. Our construction exploits the skeleton structure of the (NLO) Balitsky-Kovchegov equation, in which the first step of the evolution is explicitly singled out. The NLO impact factor is included by computing this first emission with the exact kinematics for the emitted gluon, rather than by using the eikonal approximation. This particular calculation has already been presented in the literature [1,2], but the reorganization of the perturbation theory that we propose is new. As compared to the proposal in [1,2], our scheme is free of the fine-tuning inherent in the rapidity subtraction, which might be the origin of the negativity of the NLO cross-section observed in previous studies.

54 pages, 17 pages. Substantial revision, the next-to-leading order evolution of the dipole amplitude fully included, main conclusions unchanged. Final version, to appear in JHEP

References in corpus (21)

• The Color Glass Condensate
• Universality of Unintegrated Gluon Distributions at small x
• NLO evolution of color dipoles
• Quark contribution to the small-$x$ evolution of color dipole
• Triumvirate of Running Couplings in Small-x Evolution
• Forward inclusive dijet production and azimuthal correlations in pA collisions
• Solving The High Energy Evolution Equation Including Running Coupling Corrections
• Resumming double logarithms in the QCD evolution of color dipoles
• Azimuthal correlations of forward di-hadrons in d+Au collisions at RHIC in the Color Glass Condensate
• Single Inclusive Hadron Production at RHIC and the LHC from the Color Glass Condensate
• Direct numerical solution of the coordinate space Balitsky-Kovchegov equation at next to leading order
• Single-inclusive particle production in proton-nucleus collisions at next-to-leading order in the hybrid formalism
• Particle Production at High Energy and Large Transverse Momentum - "The Hybrid Formalism" Revisited
• Photon impact factor in the next-to-leading order
• CGC predictions for p+A collisions at the LHC and signature of QCD saturation
• Quark loop contribution to BFKL evolution: Running coupling and leading-N_f NLO intercept
• Matching Collinear and Small-x Factorization Calculations for Inclusive Hadron Production in pA Collisions
• Next-to-leading order forward hadron production in the small-$x$ regime: rapidity factorization
• pT-Broadening and production processes versus dipole/quadrupole amplitudes at next-to-leading order
• Saturation in inclusive production beyond leading logarithm accuracy
• Comment on "Next-to-leading order forward hadron production in the small-x regime: rapidity factorization" arXiv:1403.5221 by Kang et al

Cited by in corpus (13)

• Dipole factorization for DIS at NLO: Combining the $q\bar{q}$ and $q\bar{q}g$ contributions
• Deep inelastic scattering in the dipole picture at next-to-leading order
• HERA data and collinearly-improved BK dynamics
• Interplay of the CGC and TMD frameworks to all orders in kinematic twist
• Pursuing the Precision Study for Color Glass Condensate in Forward Hadron Productions
• Elastic scattering of a quark from a color field: longitudinal momentum exchange
• Improvement for Color Glass Condensate factorization: single hadron production in pA collisions at next-to-leading order
• High-energy resummation in semi-hard processes at the LHC
• The non-equilibrium attractor: Beyond hydrodynamics
• Forward proton detectors in heavy ion physics
• Correlations with fluctuating strings
• Implementing consistent NLO factorization in single inclusive forward hadron production
• One-loop amplitudes with an off-shell gluon