0000000000462060
AUTHOR
Yossathorn Tawabutr
showing 2 related works from this author
Small-$x$ Quark and Gluon Helicity Contributions to the Proton Spin Puzzle
2023
A small-$x$ helicity evolution has been derived in 2016-18 and received an important modification in 2022. This proceedings discusses the setup and summarizes recent results of the theoretical development, including the asymptotic behavior of helicity PDFs and $g_1$ structure function at small $x$. The recent fits to various polarized scattering data are also discussed, together with similar calculations that follow from the same framework. The results from this research program will provide important theoretical inputs for the future polarized small-$x$ measurements at the electron-ion collider (EIC).
Quark and gluon helicity evolution at small x: revised and updated
2022
We revisit the problem of small Bjorken-$x$ evolution of the gluon and flavor-singlet quark helicity distributions in the shock wave ($s$-channel) formalism. Earlier works on the subject in the same framework resulted in an evolution equation for the gluon field-strength $F^{12}$ and quark "axial current" ${\bar\psi}\gamma^+\gamma^5\psi$ operators (sandwiched between the appropriate light-cone Wilson lines) in the double-logarithmic approximation (DLA: summing powers of $\alpha_s\,\ln^2(1/x)$ with $\alpha_s$ the strong coupling constant). In this work, we observe that an important mixing of the above operators with another gluon operator, $\overleftarrow{D}^i\,{D}^i$, also sandwiched betwee…