Sub-eikonal corrections to dipole structure functions F_L, F_T and the g1-related asymmetry are derived in a gauge-invariant dipole operator basis, with F_L shown to be finite and the others logarithmically divergent.
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Small-$x$ Helicity Evolution: an Operator Treatment
Canonical reference. 80% of citing Pith papers cite this work as background.
abstract
We rederive the small-$x$ evolution equations governing quark helicity distribution in a proton using solely an operator-based approach. In our previous works on the subject, the evolution equations were derived using a mix of diagrammatic and operator-based methods. In this work, we re-derive the double-logarithmic small-$x$ evolution equations for quark helicity in terms of the "polarized Wilson lines", the operators consisting of light-cone Wilson lines with one or two non-eikonal local operator insertions which bring in helicity dependence. For the first time we give explicit and complete expressions for the quark and gluon polarized Wilson line operators, including insertions of both the gluon and quark sub-eikonal operators. We show that the double-logarithmic small-$x$ evolution of the "polarized dipole amplitude" operators, made out of regular light-cone Wilson lines along with the polarized ones constructed here, reproduces the equations derived in our earlier works. The method we present here can be used as a template for determining the small-$x$ asymptotics of any transverse momentum-dependent (TMD) quark (or gluon) parton distribution functions (PDFs), and is not limited to helicity.
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representative citing papers
Unpolarized GPDs and GTMDs at small x with non-zero skewness are expressed via the dipole amplitude N and odderon O with modified rapidity Y = ln min{1/|x|, 1/|ξ|}.
The work establishes a correspondence between spin-dependent energy correlators and polarized TMDs/NECs using SCET, yielding N3LL/N2LL predictions for correlation patterns in current and target fragmentation regions.
Replacing the rapidity argument of the dipole amplitude with ln min{1/|x|, 1/|ξ|} and refining initial conditions for non-linear evolution can eliminate two R-factors in small-x shockwave calculations.
Review summarizing observed cold nuclear matter modifications in hadron-nucleus collision data and proposing experimental strategies for the EIC to clarify underlying QCD mechanisms.
The EIC Yellow Report specifies the science goals, required detector capabilities, and technology concepts needed to realize a high-luminosity electron-ion collider program.
citing papers explorer
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Sub-eikonal Structure of High-Energy Deep-Inelastic Scattering
Sub-eikonal corrections to dipole structure functions F_L, F_T and the g1-related asymmetry are derived in a gauge-invariant dipole operator basis, with F_L shown to be finite and the others logarithmically divergent.
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Unpolarized GPDs at small $x$ and non-zero skewness
Unpolarized GPDs and GTMDs at small x with non-zero skewness are expressed via the dipole amplitude N and odderon O with modified rapidity Y = ln min{1/|x|, 1/|ξ|}.
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Energy Correlators Resolving Proton Spin
The work establishes a correspondence between spin-dependent energy correlators and polarized TMDs/NECs using SCET, yielding N3LL/N2LL predictions for correlation patterns in current and target fragmentation regions.
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On the Two $R$-Factors in the Small-$x$ Shockwave Formalism
Replacing the rapidity argument of the dipole amplitude with ln min{1/|x|, 1/|ξ|} and refining initial conditions for non-linear evolution can eliminate two R-factors in small-x shockwave calculations.
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Nuclear Cold QCD: Review and Future Strategy
Review summarizing observed cold nuclear matter modifications in hadron-nucleus collision data and proposing experimental strategies for the EIC to clarify underlying QCD mechanisms.
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Science Requirements and Detector Concepts for the Electron-Ion Collider: EIC Yellow Report
The EIC Yellow Report specifies the science goals, required detector capabilities, and technology concepts needed to realize a high-luminosity electron-ion collider program.