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Full-Text Articles in Physics
Rapidity-Only Tmd Factorization At One Loop, Ian Balitsky
Rapidity-Only Tmd Factorization At One Loop, Ian Balitsky
Physics Faculty Publications
Typically, a production of a particle with a small transverse momentum in hadron-hadron collisions is described by CSS-based TMD factorization at moderate Bjorken xB ~ 1 and by kT-factorization at small xB. A uniform description valid for all xB is provided by rapidity-only TMD factorization developed in a series of recent papers at the tree level. In this paper the rapidity-only TMD factorization for particle production by gluon fusion is extended to the one-loop level.
Combining Nonperturbative Transverse Momentum Dependence With Tmd Evolution, J.O. Gonzalez-Hernandez, T. C. Rogers, N. Sato
Combining Nonperturbative Transverse Momentum Dependence With Tmd Evolution, J.O. Gonzalez-Hernandez, T. C. Rogers, N. Sato
Physics Faculty Publications
Central to understanding the nonperturbative, intrinsic partonic nature of hadron structure are the concepts of transverse momentum dependent (TMD) parton distribution and fragmentation functions. A TMD factorization approach to the phenomenology of semi-inclusive processes that includes evolution, higher orders, and matching to larger transverse momentum is ultimately necessary for reliably connecting with phenomenologically extracted nonperturbative structures, especially when widely different scales are involved. In this paper, we will address some of the difficulties that arise when phenomenological techniques that were originally designed for very high energy applications are extended to studies of hadron structures, and we will solidify the connection …
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 …
Resummation Of Non-Global Logarithms In Cross Sections With Massive Particles, Marcel Balsiger, Thomas Becher, Andrea Ferroglia
Resummation Of Non-Global Logarithms In Cross Sections With Massive Particles, Marcel Balsiger, Thomas Becher, Andrea Ferroglia
Publications and Research
A factorization formalism for jet processes involving massive colored particles such as the top quark is developed, extending earlier results for the massless case. The factorization of soft emissions from the underlying hard process is implemented in an effec tive field theory framework, which forms the basis for the resummation of large logarithms. The renormalization group evolution giving rise to non-global logarithms is implemented into a parton shower code in the large-Nc limit. After a comparison of the massive and massless radiation patterns, the cross section for t¯ t production with a veto on additional central jet activity is computed, …
Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato
Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato
Physics Faculty Publications
Motivated by recently observed tension between O(α2s) calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through an O(α2s) transversely differential cross section. The results confirm earlier calculations, and provide further support to the observation that tension exists with current parton distribution and fragmentation functions.
Structure Constants Of Twist-Two Light-Ray Operators In The Triple Regge Limit, Ian Balitsky
Structure Constants Of Twist-Two Light-Ray Operators In The Triple Regge Limit, Ian Balitsky
Physics Faculty Publications
The structure constants of twist-two operators with spin j in the BFKL limit g2 → 0, j → 1 and g2/j-1∼ 1 are found from the calculation of the three-point correlator of twist-two light-ray operators in the triple Regge limit. It is well known that the anomalous dimensions of twist-two operators in this limit are determined by the BFKL intercept. Similarly, the obtained structure constants are determined by an analytic function of three BFKL intercepts.
Rapidity Evolution Of Gluon Tmd From Low To Moderate X, I. Balitsky, A. Tarasov
Rapidity Evolution Of Gluon Tmd From Low To Moderate X, I. Balitsky, A. Tarasov
Physics Faculty Publications
We study how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at small x << 1 to linear evolution at moderate x ∼ 1.
Next-To-Next-To-Leading Soft-Gluon Corrections For The Top Quark Cross Section And Transverse Momentum Distribution, Nikolaos Kidonakis
Next-To-Next-To-Leading Soft-Gluon Corrections For The Top Quark Cross Section And Transverse Momentum Distribution, Nikolaos Kidonakis
Faculty and Research Publications
I present results for top quark production in hadronic collisions at LHC and Tevatron energies. The soft-gluon corrections to the differential cross section are resummed at next-to-next-to-leading-logarithm accuracy via the two-loop soft anomalous dimension matrices. Approximate next-to-next-to-leading-order differential and total cross sections are calculated. Detailed theoretical predictions are shown for the t (t) over bar cross section and the top quark p(T) distribution at the Tevatron and the LHC.
Two-Loop Soft Anomalous Dimensions For Single Top Quark Associated Production With A W- Or H-, Nikolaos Kidonakis
Two-Loop Soft Anomalous Dimensions For Single Top Quark Associated Production With A W- Or H-, Nikolaos Kidonakis
Faculty and Research Publications
I present results for the two-loop soft anomalous dimensions for associated production of a single top quark with a W boson or a charged Higgs boson. The calculation uses expressions for the massive cusp anomalous dimension, which are presented in different forms, and it allows soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. From the NNLL resummed cross section I derive approximate NNLO cross sections for bg→tW- and bg→tH- at LHC energies of 7, 10, and 14 TeV.
Theoretical Top Quark Cross Section At The Fermilab Tevatron And The Cern Lhc, Nikolaos Kidonakis, Ramona Vogt
Theoretical Top Quark Cross Section At The Fermilab Tevatron And The Cern Lhc, Nikolaos Kidonakis, Ramona Vogt
Faculty and Research Publications
We present results for the top quark pair cross section at the Tevatron and the LHC. We use the resummed double differential cross section, employing the fully kinematics-dependent soft-anomalous-dimension matrices, to calculate the soft-gluon contributions at next-to-next-to-leading order (NNLO). We improve and update our previous estimates by refining our methods, including further subleading terms, and employing the most recent parton distribution function sets. The NNLO soft corrections significantly enhance the NLO cross section while considerably reducing the scale dependence. We provide a detailed discussion of all theoretical uncertainties in our calculation, including kinematics, scale, and parton distribution uncertainties, and clarify …
Higher-Order Soft Gluon Corrections In Single Top Quark Production At The Cern Lhc, Nikolaos Kidonakis
Higher-Order Soft Gluon Corrections In Single Top Quark Production At The Cern Lhc, Nikolaos Kidonakis
Faculty and Research Publications
I present a calculation of soft-gluon corrections to single top-quark production in pp collisions at the LHC via the standard model partonic processes in the t and s channels and associated top quark and W boson production. Higher-order soft-gluon corrections through next-to-next-to-next-to-leading order (NNNLO) are calculated at next-to-leading logarithmic (NLL) accuracy. The soft-gluon corrections in the s channel and in tW production are large and dominant, while in the t channel they are not a good approximation of the complete QCD corrections.
Next-To-Next-To-Next-To-Leading-Order Soft-Gluon Corrections In Hard-Scattering Processes Near Threshold, Nikolaos Kidonakis
Next-To-Next-To-Next-To-Leading-Order Soft-Gluon Corrections In Hard-Scattering Processes Near Threshold, Nikolaos Kidonakis
Faculty and Research Publications
I present a unified calculation of soft-gluon corrections to hard-scattering cross sections through next-to-next-to-next-to-leading order (NNNLO). Master formulas are derived, from a threshold resummation formalism, that can be applied to total and differential cross sections for hard-scattering processes in hadron colliders. I also present numerical results for charged Higgs production at the LHC where these corrections are large, and for top quark production at the Tevatron where these corrections greatly reduce the scale dependence of the cross section.
Collinear And Soft Resummation In The Large-X Limit, Nikolaos Kidonakis
Collinear And Soft Resummation In The Large-X Limit, Nikolaos Kidonakis
Faculty and Research Publications
I discuss general unified formulas for resumming collinear and soft contributions to QCD hard scattering cross sections at laxge x. Expansions of the resummed cross sections to next-to-next-to-next-to-leading order are also shown along with applications of the formalism.
Global Analysis Of Data On The Proton Structure Function G₁ And The Extraction Of Its Moments, M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn, G. Ricco
Global Analysis Of Data On The Proton Structure Function G₁ And The Extraction Of Its Moments, M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn, G. Ricco
Physics Faculty Publications
Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)2. We compute for the first time low-order moments of g, and study their evolution from small to large values of Q2. The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = σ L/σT from Jefferson Lab, as well as a new model for the transverse asymmetry A2 in the resonance region. The contributions of …