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Full-Text Articles in Quantum Physics
Small-𝑥 Asmptomatics Of The Leading-Twist Flavor Singlet Quark Tmds, Daniel Adamiak, M. Gabriel Santiago, Yossathorn Tawabutr
Small-𝑥 Asmptomatics Of The Leading-Twist Flavor Singlet Quark Tmds, Daniel Adamiak, M. Gabriel Santiago, Yossathorn Tawabutr
Physics Faculty Publications
In this paper, we investigate the small-𝑥 behavior of the flavor-singlet, leading-twist quark transverse-momentum-dependent parton distribution functions (TMDs) using the light-cone operator treatment. This formalism allows us to express TMD operators at small 𝑥 in terms of polarized dipole amplitudes, enabling a systematic approach to their small-𝑥 evolution. We derive the evolution equations for these TMDs and solve them within the large-𝑁𝑐 approximation under the linearized, double-logarithmic approximation, where 𝑁𝑐 represents the number of quark colors. Expanding on previous work on unpolarized and helicity TMDs, we present the small-𝑥 asymptotics for a comprehensive set of TMDs, including the Sivers function, …
Small-X Gluon Gpd Constrained From Deeply Virtual J/Ψ Production And Gluon Pdf Through Universal-Moment Parametrization, Yuxun Guo, Xiangdong Ji, M. Gabriel Santiago, Jinghong Yang, Hao-Cheng Zhang
Small-X Gluon Gpd Constrained From Deeply Virtual J/Ψ Production And Gluon Pdf Through Universal-Moment Parametrization, Yuxun Guo, Xiangdong Ji, M. Gabriel Santiago, Jinghong Yang, Hao-Cheng Zhang
Physics Faculty Publications
We phenomenologically constrain the small-x and small-𝜉 gluon generalized parton distributions (GPDs) with the deeply virtual J/ψ production (DVJ/ψP) in the framework of GPDs through universal moment parameterization (GUMP). We use a hybrid cross-section formula combining collinear factorization to the next-to-leading order (NLO) accuracy of the strong coupling 𝛼s, with corrections from nonrelativistic QCD to account for the power corrections due to the heavy J/ψ mass. We reach reasonable fit to the measured differential cross sections of DVJ/ψP by H1 at the Hadron-Electron Ring Accelerator as well as forward gluon parton distribution functions (PDFs) from JAM22 global analysis. …
First Global Extraction Of Generalized Parton Distributions From Experiment And Lattice Data With Next-To-Leading-Order Accuracy, Yuxun Guo, Fatma P. Aslan, Xiangdong Ji, M. Gabriel Santiago
First Global Extraction Of Generalized Parton Distributions From Experiment And Lattice Data With Next-To-Leading-Order Accuracy, Yuxun Guo, Fatma P. Aslan, Xiangdong Ji, M. Gabriel Santiago
Physics Faculty Publications
We report the first global extraction of generalized parton distributions, GUMP 1.0, by combining deeply virtual Compton scattering and ρ-meson production data from Jefferson Lab and the Hadron-Electron Ring Accelerator with global fits of parton distribution functions, charge form factors, and lattice quantum chromodynamics simulations. Using a conformal moment space parametrization, we achieve a unified description across low- and high-x regions at next to leading order accuracy in perturbative corrections. The results provide state-of-the-art generalized parton distributions consistent with almost all known facts, enabling three-dimensional nucleon imaging in impact parameter space and, at the same time, establishing a benchmark for …
Collinear Factorization At Subasymptotic Kinematics And Validation In A Diquark Spectator Model, Juan V. Guerrero, Alberto Accardi
Collinear Factorization At Subasymptotic Kinematics And Validation In A Diquark Spectator Model, Juan V. Guerrero, Alberto Accardi
Physics Faculty Publications
We revisit the derivation of collinear factorization for Deep Inelastic Scattering at subasymptotic values of the four-momentum transfer squared, where the masses of the particles participating in the interaction cannot be neglected. By using an inclusive jet function to describe the scattered quark final state, we can restrict the needed parton kinematic approximations just to the four-momentum conservation of the hard scattering process, and explicitly expand the rest of the diagram in powers of the unobserved parton transverse momenta rather than neglecting those. This procedure provides one with more flexibility in fixing the virtuality of the scattered and recoiling partons …
Rapidity Evolution Of Tmds With Running Coupling, Ian Balitsky, Giovanni A. Chirilli
Rapidity Evolution Of Tmds With Running Coupling, Ian Balitsky, Giovanni A. Chirilli
Physics Faculty Publications
The scale of a coupling constant for rapidity-only evolution of transverse-momentum dependent (TMD) operators in the Sudakov kinematic region is calculated using the Brodsky-Lepage-Mackenzie optimal scale setting [S. J. Brodsky et al., Phys. Rev. D 28, 228 (1983).]. The effective argument of a coupling constant is halfway in the logarithmical scale between the transverse momentum and energy of TMD distribution. The resulting rapidity-only evolution equation is solved for quark and gluon TMDs.
Gauge-Invariant Tmd Factorization For Drell-Yan Hadronic Tensor At Small X, Ian Balitsky
Gauge-Invariant Tmd Factorization For Drell-Yan Hadronic Tensor At Small X, Ian Balitsky
Physics Faculty Publications
The Drell-Yan hadronic tensor for electromagnetic (EM) current is calculated in the Sudakov region s ≫ Q2 ≫q⊥2 with 1Q² accuracy, first at the tree level and then with the double-log accuracy. It is demonstrated that in the leading order in Nc the higher-twist quark-quark-gluon TMDs reduce to leading-twist TMDs due to QCD equation of motion. The resulting tensor for unpolarized hadrons is EM gauge-invariant and depends on two leading-twist TMDs: f1 responsible for total DY cross section, and Boer-Mulders function h1⊥. The order-of-magnitude estimates of angular distributions for DY …
Simultaneous Monte Carlo Analysis Of Parton Densities And Fragmentation Functions, Eric Moffat, W. Melnitchouk, Ted C. Rogers, N. Sato, Jefferson Lab Angular Momentum Collaboration
Simultaneous Monte Carlo Analysis Of Parton Densities And Fragmentation Functions, Eric Moffat, W. Melnitchouk, Ted C. Rogers, N. Sato, Jefferson Lab Angular Momentum Collaboration
Physics Faculty Publications
We perform a comprehensive new Monte Carlo analysis of high-energy lepton-lepton, lepton-hadron and hadron-hadron scattering data to simultaneously determine parton distribution functions (PDFs) in the proton and parton to hadron fragmentation functions (FFs). The analysis includes all available semi-inclusive deep-inelastic scattering and single-inclusive e+e− annihilation data for pions, kaons and unidentified charged hadrons, which allows the flavor dependence of the fragmentation functions to be constrained. Employing a new multistep fitting strategy and more flexible parametrizations for both PDFs and FFs, we assess the impact of different datasets on sea quark densities and confirm the previously observed suppression …
Measurement Of Deeply Virtual Compton Scattering Off 4He With The Cebaf Large Acceptance Spectrometer At Jefferson Lab, Clas Collaboration, R. Dupré, Mohammad Hattawy, N. A. Batzell, Stephen Bültmann, Bayram Torayev, Moskov Amaryan, Dilini L. Bulumulla, M. Mayer, David C. Payette, Yelena Prok, Jiwan Poudel, Lawrence B. Weinstein, B. Yale, N. Zachariou, J. Zhang, Et Al.
Measurement Of Deeply Virtual Compton Scattering Off 4He With The Cebaf Large Acceptance Spectrometer At Jefferson Lab, Clas Collaboration, R. Dupré, Mohammad Hattawy, N. A. Batzell, Stephen Bültmann, Bayram Torayev, Moskov Amaryan, Dilini L. Bulumulla, M. Mayer, David C. Payette, Yelena Prok, Jiwan Poudel, Lawrence B. Weinstein, B. Yale, N. Zachariou, J. Zhang, Et Al.
Physics Faculty Publications
We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off 4He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized 4He gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling 4He nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the …
Drell-Yan Angular Lepton Distributions At Small X From Tmd Factorization, Ian Balitsky
Drell-Yan Angular Lepton Distributions At Small X From Tmd Factorization, Ian Balitsky
Physics Faculty Publications
The Drell-Yan process is studied in the framework of TMD factorization in the Sudakov region s » Q2 » q2⊥ corresponding to recent LHC experiments with Q2 of order of mass of Z-boson and transverse momentum of DY pair ∼ few tens GeV. The DY hadronic tensors are expressed in terms of quark and quark-gluon TMDs with 1Q2 and 1Nc2 accuracy. It is demonstrated that in the leading order in Nc the higher-twist quark-quark-gluon TMDs reduce to leading-twist TMDs due to QCD equation of motion. The resulting hadronic tensors depend on …
Double Inclusive Small-X Gluon Production And Their Azimuthal Correlations In A Biased Ensemble, Gary Kapilevich
Double Inclusive Small-X Gluon Production And Their Azimuthal Correlations In A Biased Ensemble, Gary Kapilevich
Publications and Research
We consider double gg → g production in the presence of a bias on the unintegrated gluon distribution of the colliding hadrons or nuclei. Such bias could be due to the selection of configurations with a greater number of gluons or higher mean transverse momentum squared or, more generally, due to a modified spectral shape of the gluon distribution in the hadrons. Hence, we consider reweighted functional averages over the stochastic ensemble of small-x gluons. We evaluate explicitly the double inclusive gluon transverse momentum spectrum in high-energy collisions, and their azimuthal correlations, for a few simple examples of biases.
Origin Of Single Transverse-Spin Asymmetries In High-Energy Collisions, Justin Cammarota, Leonard Gamberg, Zhong-Bo Kang, Joshua A. Miller, Daniel Pitonyak, Alexei Prokudin, Ted C. Rogers, Nobuo Sato
Origin Of Single Transverse-Spin Asymmetries In High-Energy Collisions, Justin Cammarota, Leonard Gamberg, Zhong-Bo Kang, Joshua A. Miller, Daniel Pitonyak, Alexei Prokudin, Ted C. Rogers, Nobuo Sato
Physics Faculty Publications
In this paper, we perform the first simultaneous QCD global analysis of data from semi-inclusive deep inelastic scattering, Drell-Yan, 𝑒+𝑒− annihilation into hadron pairs, and proton-proton collisions. Consequently, we are able to extract a universal set of nonperturbative functions that describes the observed asymmetries in these reactions. The outcome of our analysis indicates single transverse-spin asymmetries in high-energy collisions have a common origin. Furthermore, we achieve the first phenomenological agreement with lattice QCD on the up and down quark tensor charges.
Master Integrals For The Two-Loop, Non-Planar Qcd Corrections To Top-Quark Pair Production In The Quark-Annihilation Channel, Matteo Becchetti, Roberto Bonciani, Valerio Casconi, Andrea Ferroglia, Simone Lavacca, Andreas Von Manteuffel
Master Integrals For The Two-Loop, Non-Planar Qcd Corrections To Top-Quark Pair Production In The Quark-Annihilation Channel, Matteo Becchetti, Roberto Bonciani, Valerio Casconi, Andrea Ferroglia, Simone Lavacca, Andreas Von Manteuffel
Publications and Research
We present the analytic calculation of the Master Integrals for the two-loop, non-planar topologies that enter the calculation of the amplitude for top-quark pair hadroproduction in the quark-annihilation channel. Using the method of differential equations, we expand the integrals in powers of the dimensional regulator ε and determine the expansion coefficients in terms of generalized harmonic polylogarithms of two dimensionless variables through to weight four.
What Does Kinematical Target Mass Sensitivity In Dis Reveal About Hadron Structure?, E. Moffat, T. C. Rogers, W. Melnitchouk, N. Sato, F. Steffans
What Does Kinematical Target Mass Sensitivity In Dis Reveal About Hadron Structure?, E. Moffat, T. C. Rogers, W. Melnitchouk, N. Sato, F. Steffans
Physics Faculty Publications
We study the role of purely external kinematical approximations in inclusive deep-inelastic lepton–hadron scattering within QCD factorization, and consider factorization with an exact treatment of the target hadron mass. We discuss how an observed phenomenological improvement obtained by accounting for target mass kinematics could be interpreted in terms of general properties of target structure, and argue that such an improvement implies a hierarchy of nonperturbative scales within the hadron.