Gluon orbital angular momentum at small-$x$

Abstract

We present a general analysis of the orbital angular momentum (OAM) distribution of gluons $L_g(x)$ inside the nucleon with particular emphasis on the small-$x$ region. We derive a novel operator representation of $L_g(x)$ in terms of Wilson lines and argue that it is approximately proportional to the gluon helicity distribution $L_g(x)\approx -2\Delta G(x)$ at small-$x$. We also compute longitudinal single spin asymmetry in exclusive diffractive dijet production in lepton-nucleon scattering in the next-to-eikonal approximation and show that the asymmetry is a direct probe of the gluon helicity/OAM distribution as well as the QCD odderon exchange.

22 pages. v2 significantly expands the previous version with all the details of derivation as well as a number of new results and discussions. The title and abstract are changed, and an author is added

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Cited by in corpus (51)

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• The Present and Future of QCD
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• Proton Spin Structure at Small-$x$
• Quarks at next-to-eikonal accuracy in the CGC I: Forward quark-nucleus scattering
• High-energy Operator Product Expansion at sub-eikonal level
• Helicity-dependent extension of the McLerran-Venugopalan model
• Quark Sivers Function at Small $x$: Spin-Dependent Odderon and the Sub-Eikonal Evolution
• Quark and scalar propagators at next-to-eikonal accuracy in the CGC through a dynamical background gluon field
• Quark and Gluon Helicity Evolution at Small $x$: Revised and Updated
• Helicity at Small $x$: Oscillations Generated by Bringing Back the Quarks
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• Helicity Evolution at Small $x$: the Single-Logarithmic Contribution
• A novel formulation of the unintegrated gluon distribution for DIS
• First analysis of world polarized DIS data with small-$x$ helicity evolution
• Semi-inclusive Diffractive Deep Inelastic Scattering at Small-$x$
• Towards a complete next-to-logarithmic description of forward exclusive diffractive dijet electroproduction at HERA: real corrections
• Probing the Sivers function with an unpolarized target: GTMD distributions and the Odderons
• DIS dijet production at next-to-eikonal accuracy in the CGC
• Analytic Solution for the Revised Helicity Evolution at Small $x$ and Large $N_c$: New Resummed Gluon-Gluon Polarized Anomalous Dimension and Intercept
• T-odd Leading-Twist Quark TMDs at Small $x$
• Wigner Distributions For Gluons
• Sea quark Sivers distribution
• Probing the gluon tomography in photoproduction of di-pions
• Gluon-mediated inclusive Deep Inelastic Scattering from Regge to Bjorken kinematics
• QCD Resummation in Hard Diffractive Dijet Production at the Electron-Ion Collider
• Prospects for quarkonium studies at the high-luminosity LHC
• Helicity Evolution at Small $x$: Revised Asymptotic Results at Large $N_c\&N_f$
• Leading twist GTMDs at nonzero skewness and Wigner distributions in boost-invariant longitudinal position space
• Small-x Evolution of the Gluon Generalized Parton Distribution Eg of the Nucleon
• Lensing Mechanism Meets Small-$x$ Physics: Single Transverse Spin Asymmetry in $p^{\uparrow }+p$ and $p^{\uparrow }+A$ Collisions
• Quark Wigner Distributions and GTMDs of Pion in the Light-Front Holographic Model
• On the small-$x$ behavior of the orbital angular momentum distributions in QCD
• Wigner distributions for an electron
• Global analysis of polarized DIS & SIDIS data with improved small-$x$ helicity evolution
• Quark generalized TMDs at skewness and Wigner Distribution in boost invariant longitudinal space
• GTMDs and the factorization of exclusive double Drell-Yan
• QCD evolution of the orbital angular momentum of quarks and gluons: Genuine twist-three part
• Proton spin after 30 years: what we know and what we don't?
• Spin-flip gluon GTMD $F_{1,2}$ at small-$x$
• Wigner distributions and GTMDs in a proton using light-front quark-diquark model
• Quark TMDs from back-to-back dijet production at forward rapidities in pA collisions beyond eikonal accuracy in the CGC
• Gluon generalized transverse momentum dependent parton distributions and Wigner functions of the Proton
• Parton model contributions as next-to-eikonal corrections to the dipole factorization of DIS and SIDIS at low $x_{Bj}$
• Small-$x$ evolution of dipole amplitude in momentum space: forward--off-forward correspondence
• Three Dimensional Imaging of the Nucleon
• Orbital Angular Momentum Distribution of Gluons at Small-$x$ : Analytic interpolation between Ji and Jaffe-Manohar
• T-odd Wigner Distributions in boost-invariant longitudinal position space and Spin-momentum correlation in proton