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DOE OSTI · 1579283

Helicity-dependent generalization of the JIMWLK evolution

Cougoulic, Florian·Kovchegov, Yuri V.
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Abstract

We generalize the JIMWLK evolution equation to include the small-$x$ evolution of helicity distributions. To derive helicity JIMWLK, we use the method devised by A.H. Mueller in [Phys. Lett. B 523, 243 (2001)] for the usual unpolarized JIMWLK, and apply it to the helicity evolution equations derived in J. High Energy Phys. 01 (2016) 072; Phys. Rev. D 95, 014033 (2017); J. High Energy Phys. 10 (2017) 198; Phys. Rev. D 99, 054032 (2019)]. We obtain a functional evolution equation for the generalized JIMWLK weight functional. The functional now is a sum of a helicity-independent term and a helicity-dependent term. The kernel of the new evolution equation consists of the standard eikonal leading-order JIMWLK kernel plus new terms containing derivatives with respect to the sub-eikonal quark and gluon fields. The new kernel we derive can be used to generate the standard JIMWLK evolution and to construct small-$x$ evolution equations for flavor-singlet operators made of any number of light-cone Wilson lines along with one Wilson line containing sub-eikonal helicity-dependent local operator insertions (a "polarized Wilson line").

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73 NUCLEAR PHYSICS AND RADIATION PHYSICSElectron-Ion Colliderhelicityperturbative QCDproton spin

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BibTeXRIS

Cougoulic, Florian, Kovchegov, Yuri V.. 2019-12-11. Helicity-dependent generalization of the JIMWLK evolution. https://doi.org/10.1103/physrevd.100.114020

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