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1. QCD evolution of the gluon Sivers function in heavy flavor dijet production at the Electron-Ion Collider

   https://doi.org/10.1007/JHEP05(2021)286  

   Kang, Zhong-Bo; Reiten, Jared; Shao, Ding Yu; Terry, John (May 2021, Journal of High Energy Physics)

   null (Ed.)

   A bstract Using Soft-Collinear Effective Theory, we develop the transverse-momentum-dependent factorization formalism for heavy flavor dijet production in polarized-proton-electron collisions. We consider heavy flavor mass corrections in the collinear-soft and jet functions, as well as the associated evolution equations. Using this formalism, we generate a prediction for the gluon Sivers asymmetry for charm and bottom dijet production at the future Electron-Ion Collider. Furthermore, we compare theoretical predictions with and without the inclusion of finite quark masses. We find that the heavy flavor mass effects can give sizable corrections to the predicted asymmetry. 

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2. Dijet spectrum in nonlocal and asymptotically nonlocal theories

   https://doi.org/10.1103/PhysRevD.110.055018  

   Anderson, Mikkie R; Carone, Christopher D (September 2024, Physical Review D)

   Asymptotically nonlocal field theories approximate ghost-free nonlocal theories at low energies, yet are theories of finite order in the number of derivatives. These theories have an emergent nonlocal scale that regulates loop diagrams and can provide a solution to the hierarchy problem. Asymptotic nonlocality has been studied previously in scalar theories, Abelian and non-Abelian gauge theories with complex scalars, and linearized gravity. Here we extend that work by considering an asymptotically nonlocal generalization of QCD, which can be used for realistic phenomenological investigations. In particular, we derive Feynman rules relevant for the study of the production of dijets at hadron colliders and compute the parton-level cross sections at leading order. We use these to determine a bound on the scale of new physics from Large Hadron Collider data, both for a typical choice of model parameters, and in the nonlocal limit. 

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3. The Sivers asymmetry in hadronic dijet production

   https://doi.org/10.1007/JHEP02(2021)066  

   Kang, Zhong-Bo; Lee, Kyle; Shao, Ding Yu; Terry, John (February 2021, Journal of High Energy Physics)

   null (Ed.)

   A bstract We study the single spin asymmetry in the back-to-back dijet production in transversely polarized proton-proton collisions. Such an asymmetry is generated by the Sivers functions in the incoming polarized proton. We propose a QCD formalism in terms of the transverse momentum dependent parton distribution functions, which allow us to resum the large logarithms that arise in the perturbative calculations. We make predictions for the Sivers asymmetry of hadronic dijet production at the kinematic region that is relevant to the experiment at the Relativistic Heavy Ion Collider (RHIC). We further compute the spin asymmetries in the selected positive and negative jet charge bins, to separate the contributions from u - and d -quark Sivers functions. We find that both the sign and size of our numerical results are roughly consistent with the preliminary results from the STAR collaboration at the RHIC. 

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4. Parton rescattering and gluon saturation in dijet production at EIC

   https://doi.org/10.1103/PhysRevD.105.034015  

   Zhang, Yuan-Yuan; Wang, Xin-Nian (February 2022, Physical Review D)
5. QCD resummation of dijet azimuthal decorrelations in pp and pA collisions

   https://doi.org/10.1007/JHEP10(2023)013  

   Gao, Mei-Sen; Kang, Zhong-Bo; Shao, Ding Yu; Terry, John; Zhang, Cheng (October 2023, Journal of High Energy Physics)

   A<sc>bstract</sc> We study the azimuthal angular decorrelations of dijet production in both proton-proton (pp) and proton-nucleus (pA) collisions. By utilizing soft-collinear effective theory, we establish the factorization and resummation formalism at the next-to-leading logarithmic accuracy for the azimuthal angular decorrelations in the back-to-back limit in pp collisions. We propose an approach where the nuclear modifications to dijet production in pA collisions are accounted for in the nuclear modified transverse momentum dependent parton distribution functions (nTMDPDFs), which contain both collinear and transverse dynamics. This approach naturally generalizes the well-established formalism related to the nuclear modified collinear parton distribution functions (nPDFs). We demonstrate strong consistency between our methodology and the CMS measurements in both pp and pA collisions, and make predictions for dijet production in the forward rapidity region in pA collisions at LHC kinematics and for mid-rapidity kinematics at sPHENIX. Throughout this paper, we focus on the application of this formalism to a simultaneous fit to both collinear and transverse momentum dependent contributions to the transverse momentum dependent distributions. 

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