First analysis of world polarized SIDIS data with small-$x$ helicity evolution

We use small-$x$ helicity evolution equations to analyze the world polarized DIS and Semi-inclusive DIS (SIDIS) data. After successfully describing the $g_1$ structure function extracted from polarized DIS, we extend this analysis to the small-$x$ $g^h_1$ structure function measured in polarized SIDIS. The fit is performed through a Monte-Carlo analysis within the JAM global framework. Combining the DIS and SIDIS data we are able to extract the individual helicity PDFs for both the light quarks and light anti-quarks. The advantage of our approach is that our evolution predicts the small-$x$ behavior of these helicity distributions, allowing for a precise extrapolation of our helicity PDFs to smaller values of $x$, in the region that cannot be accessed experimentally. This brings us one step closer to resolving the proton spin problem.