Transverse energy-energy correlators in the color-glass condensate at the electron-ion collider

We investigate the transverse energy-energy correlators (TEEC) in the small-<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>x</a:mi></a:mrow></a:math> regime at the upcoming Electron-Ion Collider (EIC). Focusing on the back-to-back production of electron-hadron pairs in both <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>e</c:mi><c:mi>p</c:mi></c:math> and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>e</e:mi><e:mi>A</e:mi></e:math> collisions, we establish a factorization formula given in terms of the hard function, quark distributions, soft functions, and TEEC jet functions, where the gluon saturation effect is incorporated. Numerical results for TEEC in both <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>e</g:mi><g:mi>p</g:mi></g:math> and <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi>e</i:mi><i:mi>A</i:mi></i:math> collisions are presented, together with the nuclear modification factor <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:msub><k:mi>R</k:mi><k:mi>A</k:mi></k:msub></k:math>. Our analysis reveals that TEEC observables in deep inelastic scattering provide a valuable approach for probing gluon saturation phenomena. Our findings underscore the significance of measuring TEEC at the EIC, emphasizing its efficacy in advancing our understanding of gluon saturation and nuclear modifications in high-energy collisions.