Friday·January 6, 2023

Nucleon Energy Correlators for the Color Glass Condensate

Hao-Yu Liu🇨🇳 · Xiaohui Liu🇨🇳 · Ji-Chen Pan🇨🇳 · Feng Yuan🇺🇸 · Hua Xing Zhu🇨🇳

We demonstrate the recently proposed nucleon energy-energy correlator (nucleon EEC) $f_{\mathrm{EEC}}(x,\theta )$ can unveil the gluon saturation in the small-$x$ regime in $eA$ collisions. The novelty of this probe is that it is fully inclusive just like the deep-inelastic scattering (DIS), with no requirements of jets or hadrons, but still provides an evident portal to the small-$x$ dynamics through the shape of the $\theta$-distribution. We find that the saturation prediction is significantly different from the expectation of the collinear factorization.