Inclusive prompt photon-jet correlations as a probe of gluon saturation in electron-nucleus scattering at small $x$

Abstract

We compute the differential cross-section for inclusive prompt photon$+$quark production in deeply inelastic scattering of electrons off nuclei at small $x$ ($e+A$ DIS) in the framework of the Color Glass Condensate effective field theory. The result is expressed as a convolution of the leading order (in the strong coupling ${\alpha }_{\mathrm{s}}$) impact factor for the process and universal dipole matrix elements, in the limit of hard photon transverse momentum relative to the nuclear saturation scale $Q_{s,A}(x)$. We perform a numerical study of this process for the kinematics of the Electron-Ion Collider (EIC), exploring in particular the azimuthal angle correlations between the final state photon and quark. We observe a systematic suppression and broadening pattern of the back-to-back peak in the relative azimuthal angle distribution, as the saturation scale is increased by replacing proton targets with gold nuclei. Our results suggest that photon+jet final states in inclusive $e+A$ DIS at high energies are in general a promising channel for exploring gluon saturation that is complementary to inclusive and diffractive dijet production. They also provide a sensitive empirical test of the universality of dipole matrix elements when compared to identical measurements in proton-nucleus collisions. However because photon+jet correlations at small $x$ in EIC kinematics require jet reconstruction at small $k_{\perp }$, it will be important to study their feasibility relative to photon-hadron correlations.

41 pages, 7 figures

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• 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
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• Azimuthal correlations of forward di-hadrons in d+Au collisions at RHIC in the Color Glass Condensate
• kt-factorization for Hard Processes in Nuclei
• Direct numerical solution of the coordinate space Balitsky-Kovchegov equation at next to leading order
• Forward dihadron correlations in deuteron-gold collisions with a Gaussian approximation of JIMWLK
• Forward di-jet production in p+Pb collisions in the small-x improved TMD factorization framework
• Sudakov Resummation in Small-x Saturation Formalism
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• Measuring the Photon Fragmentation Function at HERA
• Prompt photon - jet angular correlations at central rapidities in p+A collisions
• Saturation physics and angular correlations at RHIC and LHC
• Photon-Jet cross sections in Deep-Inelastic Scattering

Cited by in corpus (19)

• Mining for Gluon Saturation at Colliders
• The importance of kinematic twists and genuine saturation effects in dijet production at the Electron-Ion Collider
• Nucleon Energy Correlators for the Color Glass Condensate
• Revisiting transverse momentum broadening in dense QCD media
• Exclusive J/Psi and Psi(2s) photo-production as a probe of QCD low x evolution equations
• One-Loop Corrections to Dihadron Production in DIS at Small $x$
• Single Inclusive Hadron Production in DIS at Small $x$: Next to Leading Order Corrections
• Isolated photon-hadron production in high energy $pp$ and $pA$ collisions at RHIC and LHC
• Harmonics of Parton Saturation in Lepton-Jet Correlations at the EIC
• Single Inclusive Jet Production in $pA$ Collisions at NLO in the small-$x$ regime
• Nuclear matter effects on jet production at electron-ion colliders
• Dihadron Production in DIS at Small $x$ at Next to Leading Order: Transverse Photons
• Saturation effects in SIDIS at very forward rapidities
• Probing gluon number density with electron-dijet correlations at EIC
• Electroproduction of heavy quarkonia: significance of dipole orientation
• TMD parton showers for associated $\gamma$+jet production in electron-proton collisions at high energies
• Probing cold nuclear matter with energy correlators
• Dijet impact factor in DIS at next-to-leading order in the Color Glass Condensate
• Gluon imaging using azimuthal correlations in diffractive scattering at the Electron-Ion Collider