NUC In the literature: open

Which Electron-Ion Collider measurement can decide on gluon saturation?

In plain words

The Electron-Ion Collider, being built at Brookhaven, is designed to settle whether gluons saturate. Which of its many possible measurements gives the cleanest yes or no, given its limited reach to small momentum fractions, still has to be determined.

Precise statement

Within the Electron-Ion Collider kinematic range for $e+\mathrm{Au}$, identify the observable or combination (ratio of diffractive to inclusive cross sections in eA versus ep, the longitudinal structure function $F_{L}^{A}$, dihadron azimuthal decorrelation, coherent and incoherent vector-meson $\mid t\mid$ spectra) that discriminates nonlinear from linear evolution at more than $5\sigma$, with realistic luminosity and systematic uncertainties. The answer is a ranked list with projected significances.

What would settle it

Impact studies using full detector simulation and both classes of theory with common inputs, followed by the measurement itself.

Status in the literature

Unverified note

The EIC is under construction at Brookhaven with operations planned for the 2030s.