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Title: Which Electron-Ion Collider measurement can decide on gluon saturation?
Plain: 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: 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.
Settled by: Impact studies using full detector simulation and both classes of theory with common inputs, followed by the measurement itself.
Kind: well-posed
Answer type: identification
References: (empty)
Literature status: open
Status note: The EIC is under construction at Brookhaven with operations planned for the 2030s.
Posed since: (empty)