Back-to-back inclusive dijets in DIS at small $x$: Sudakov suppression and gluon saturation at NLO

Abstract

Back-to-back dijet cross-sections in deeply inelastic scattering (DIS) at small $x_{\mathrm{Bj}}$ are suppressed by many-body multiple scattering and screening effects arising from gluon saturation at high parton densities. They are similarly sensitive in these kinematics to large Sudakov logarithms from soft gluon radiation. Uncovering novel physics in this DIS channel therefore requires understanding the interplay of the two phenomena. In this work, we compute the small $x_{\mathrm{Bj}}$ inclusive dijet DIS cross-section in back-to-back kinematics at next-to-leading order (NLO) in the Color Glass Condensate effective field theory (CGC EFT). Our result includes, for the first time, all real and virtual NLO contributions to the impact factor. These include all Sudakov double and single logarithm contributions, as well as all other finite $\mathcal{O}({\alpha }_s)$ terms that contribute at this order. We demonstrate explicitly that resummations of small $x$ and Sudakov logarithms can be performed simultaneously in the CGC EFT. This requires that the JIMWLK kernel for small $x$ evolution of the Weizsäcker-Williams (WW) gluon distribution satisfies a kinematic constraint imposed by lifetime ordering of successive gluon emissions; the corresponding modifications to the kernel, corresponding to resummations of large double transverse logarithms, are precisely of the type required to stabilize JIMWLK evolution beyond leading logarithmic accuracy. We compute the azimuthal harmonics of the NLO back-to-back distributions and show their sensitivity to both the unpolarized and linearly polarized WW gluon distributions. Finally, we discuss how TMD factorization is broken by an emergent saturation scale at small $x$.

v2: added subsection 5.3 summarizing results, matches the published version. v1: 77 pages, 3 figures, 1 table

References in corpus (23)

• The Color Glass Condensate
• Universality of Unintegrated Gluon Distributions at small x
• NLO evolution of color dipoles
• Forward inclusive dijet production and azimuthal correlations in pA collisions
• A practical Seedless Infrared-Safe Cone jet algorithm
• Resumming double logarithms in the QCD evolution of color dipoles
• kt-factorization for Hard Processes in Nuclei
• The Construction of Gauge-Links in Arbitrary Hard Processes
• Mining for Gluon Saturation at Colliders
• Forward dihadron correlations in deuteron-gold collisions with a Gaussian approximation of JIMWLK
• Single-inclusive particle production in proton-nucleus collisions at next-to-leading order in the hybrid formalism
• Forward di-jet production in p+Pb collisions in the small-x improved TMD factorization framework
• Photon impact factor in the next-to-leading order
• Non-linear evolution in QCD at high-energy beyond leading order
• High Gluon Densities in Heavy Ions Collisions
• Probing Gluon Saturation through Dihadron Correlations at an Electron-Ion Collider
• Soft Gluon Resummations in Dijet Azimuthal Angular Correlations at the Collider
• NLO JIMWLK evolution unabridged
• Probing gluon saturation with next-to-leading order photon production at central rapidities in proton-nucleus collisions
• Interplay of the CGC and TMD frameworks to all orders in kinematic twist
• Pursuing the Precision Study for Color Glass Condensate in Forward Hadron Productions
• One-Loop Corrections to Dihadron Production in DIS at Small $x$
• Probing gluon number density with electron-dijet correlations at EIC

Cited by in corpus (1)

• Dihadron Production in DIS at Small $x$ at Next to Leading Order: Transverse Photons