Orateur
Description
We analyze the world polarized deep-inelastic scattering (DIS) and semi-inclusive DIS (SIDIS) data at $x < 0.1$, using small-$x$ evolution equations at the more realistic large-$N_c\& N_f$ limit for the flavor singlet and nonsinglet helicity parton distribution functions (hPDFs), which resum all powers of both $\alpha_s\ln^2(1/x)$ and $\alpha_s\ln(1/x)\ln(Q^2/Q^2_0)$ with $\alpha_s$ the strong coupling constant. The hPDFs for quarks, antiquarks and gluons are extracted and evolved to lower values of $x$ to make predictions for the future Electron-Ion Collider (EIC). While the existing low-$x$ polarized DIS and SIDIS data are insufficient to constrain the "Born-inspired" initial conditions currently employed for the polarized dipole amplitudes in the helicity evolution equations, future EIC data will allow more precise predictions for hPDFs and the $g_1$ structure function for values of $x$ beyond those probed at the EIC. Based on the obtained hPDFs, the contributions to the proton spin from quark and gluon spins at small $x$ will be discussed.
