Constraining hot and cold nuclear matter properties from heavy-ion collisions and deep-inelastic scattering

We perform a global analysis of deep-inelastic $e+p$ scattering data from HERA and transverse energy distributions in $p+p$ and $p+\mathrm{P}\mathrm{b}$ collisions, alongside charged hadron multiplicities in $\mathrm{P}\mathrm{b}+\mathrm{P}\mathrm{b}$ collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}=5.02\mathrm{T}\mathrm{e}\mathrm{V}$ from ALICE. Using a saturation-based initial state model grounded in high-energy QCD, we determine the early-time non-equilibrium shear viscosity to entropy density ratio $\eta \mathrm{/}s$ of the quark-gluon plasma. Our results provide new insights into the early-time transport properties of nuclear matter under extreme conditions.