Complete Next-to-Leading Order Calculation of Single Inclusive ${\pi }^0$ Production in Forward Proton-Nucleus Collisions

Abstract

We present the first fully consistent calculation of inclusive ${\pi }^0$ production at forward rapidities at next-to-leading order (NLO) accuracy in proton-lead collisions at $\sqrt{s}=8.16$ TeV within the Color Glass Condensate approach. The center-of-mass energy dependence is determined by the Balitsky-Kovchegov equation with the initial condition constrained at NLO accuracy by the proton structure function measurements. We find that the LHCb data further constrain this non-perturbative input, and that both the NLO corrections to the evolution equation and to the impact factor have significant effects on the nuclear modification factor $R_{p\mathrm{Pb}}$. The complete NLO calculation is shown to be in qualitative agreement with the LHCb data, and the predictions are found to be sensitive to the details of the applied deep inelastic scattering (DIS) fit. These results demonstrate the need to perform global analyses of DIS and LHC data in order to probe gluon saturation phenomena at precision level at very small momentum fraction $x$.

15 pages, 8 figures

References in corpus (22)

• Parton distributions for the LHC
• The Color Glass Condensate
• Global analysis of fragmentation functions for pions and kaons and their uncertainties
• NLO evolution of color dipoles
• Resumming double logarithms in the QCD evolution of color dipoles
• CGC predictions for p+Pb collisions at the LHC
• Single Inclusive Hadron Production at RHIC and the LHC from the Color Glass Condensate
• Forward Neutral Pion Production in p+p and d+Au Collisions at sqrt(s_NN)=200 GeV
• Mining for Gluon Saturation at Colliders
• 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
• Forward $J/\psi$ production in proton-nucleus collisions at high energy
• Non-linear evolution in QCD at high-energy beyond leading order
• CGC factorization for forward particle production in proton-nucleus collisions at next-to-leading order
• Dipole factorization for DIS at NLO: Combining the $q\bar{q}$ and $q\bar{q}g$ contributions
• Massive quarks at one loop in the dipole picture of Deep Inelastic Scattering
• Pursuing the Precision Study for Color Glass Condensate in Forward Hadron Productions
• Measurement of the nuclear modification factor and prompt charged particle production in $p\mathrm{Pb}$ and $pp$ collisions at $\sqrt{s_{\mathrm{NN}}}=5\mathrm{TeV}$
• Proton structure functions at NLO in the dipole picture with massive quarks
• Saturation and forward jets in proton-lead collisions at the LHC
• High-energy dipole scattering amplitude from evolution of low-energy proton light-cone wave functions
• Nuclear modification factor of neutral pions in the forward and backward regions in $p$-Pb collisions

Cited by in corpus (5)

• Energy dependent nuclear suppression from gluon saturation in exclusive vector meson production
• Inferring the initial condition for the Balitsky-Kovchegov equation
• Initial condition for the Balitsky-Kovchegov equation at next-to-leading order
• Quark TMDs from back-to-back dijet production at forward rapidities in pA collisions beyond eikonal accuracy in the CGC
• Physics with high-luminosity proton-nucleus collisions at the LHC