Do we expect light flavor sea-quark asymmetry also for the spin-dependent distribution functions of the nucleon?

The theoretical predictions of the chiral quark soliton model for the unpolarized and longitudinally polarized structure functions of the nucleon are compared with recent high energy data. The theory is shown to explain all the qualitative features of the experiments, including the NMC data for $F_2^p\mathrm{}\left(x\right)\mathrm{}-F_2^n\mathrm{}\left(x\right),$ $F_2^n{\mathrm{}\left(x\right)/F}_2^p\mathrm{}\left(x\right),$ the Hermes and NuSea data for $\overline{d}\mathrm{}\left(x\right)\mathrm{}-ū\mathrm{}\left(x\right),$ and the EMC and SMC data for $g_1^p\mathrm{}\left(x\right),$ $g_1^n\mathrm{}\left(x\right)\mathrm{}$ and $g_1^d\mathrm{}\left(x\right).$ It also predicts at $Q^2=4\mathrm{}\mathrm{GeV}$ that $\Delta \overline{d}\mathrm{}\left(x\right)\mathrm{}-\Delta ū{\mathrm{}\left(x\right)=Cx}^{\alpha }\left[\overline{d}\mathrm{}\right(x\left)\mathrm{}-ū\mathrm{}\right(x\left)\mathrm{}\right]$ with a sizable negative coefficient $C\simeq -2.0$ (and $\alpha \simeq 0.12),$ thereby strongly indicating light flavor sea-quark asymmetry also for the longitudinally polarized distribution functions.