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Transverse-momentum-dependent parton distributions (TMDs) can be calculated from first principles by computing a related set of Euclidean lattice observables and connecting them via a factorization formula. This work focuses on the…

High Energy Physics - Phenomenology · Physics 2022-09-19 Stella T. Schindler , Iain W. Stewart , Yong Zhao

Using the framework of the non-local light-cone expansion a systematic study is performed for the structure of the twist-2 contributions to the virtual Compton amplitude in polarized deep-inelastic non-forward scattering for general nucleon…

High Energy Physics - Phenomenology · Physics 2009-11-07 Johannes Blümlein , Jörg Eilers , Bodo Geyer , Dieter Robaschik

We present a determination of the structure functions of the off-forward Compton amplitude $\mathcal{H}_1$ and $\mathcal{E}_1$ from the Feynman-Hellmann method in lattice QCD. At leading twist, these structure functions give access to the…

High Energy Physics - Lattice · Physics 2024-07-11 A. Hannaford-Gunn , K. U. Can , J. A. Crawford , R. Horsley , P. E. L. Rakow , G. Schierholz , H. Stüben , R. D. Young , J. M. Zanotti

Power corrections to the Q**2 behavior of the Nachtmann moments of the proton polarized structure function g1p are investigated at large Bjorken-x by developing a phenomenological fit of both the resonance (including the photon point) and…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Simula , M. Osipenko , G. Ricco , M. Taiuti

We present a new truncation scheme for the Schwinger-Dyson equations of QCD that respects gauge invariance at any level of the dressed loop expansion. When applied to the gluon self-energy, it allows for its non-perturbative treatment…

High Energy Physics - Phenomenology · Physics 2008-11-26 Daniele Binosi , Joannis Papavassiliou

In the semiclassical approach, inclusive and diffractive quark and gluon distributions are expressed in terms of correlation functions of Wilson loops. Each Wilson loop integrates the colour field strength in the area between the…

High Energy Physics - Phenomenology · Physics 2010-03-25 W. Buchmuller , T. Gehrmann , A. Hebecker

We obtain all the leading-twist quark generalized parton distributions (GPDs) inside the proton at nonzero skewness within the basis light-front quantization framework. We employ the light-front wave functions of the proton from a…

High Energy Physics - Phenomenology · Physics 2024-03-12 Yiping Liu , Siqi Xu , Chandan Mondal , Xingbo Zhao , James P. Vary

The ratio g1/F1 has been measured over the range 0.03<x<0.6 and 0.3<Q2<10 (GeV/c)2 using deep-inelastic scattering of polarized electrons from polarized protons and deuterons. We find g1/F1 to be consistent with no Q2-dependence at fixed x…

High Energy Physics - Experiment · Physics 2008-11-26 The E143 Collaboration , K. Abe et al

The twist three contributions to the $Q^2$-evolution of the spin-dependent structure function $g_2(x_{Bj},Q^2)$ are considered in the non-local operator product approach. Defining appropriate twist three distribution function we derive…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Geyer , D. Müller , D. Robaschik

An approach is described to calculate Generalized Parton Distributions (GPDs) in Constituent Quark Models (CQM). The GPDs are obtained from wave functions to be evaluated in a given CQM. The general relations linking the twist-two GPDs to…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Scopetta , V. Vento

We consider the anomalous dimension $\gamma_{gg}^{(3)}(N)$ of the twist-two gluon operator of arbitrary Lorentz spin $N$ in the quark flavor singlet sector of a general gauge theory at four loops and construct its contribution proportional…

High Energy Physics - Phenomenology · Physics 2026-04-29 B. A. Kniehl , S. -O. Moch , V. N. Velizhanin , A. Vogt

We evaluate the one-loop four-graviton scattering amplitude in type-II superstring theory exactly in $\alpha'$. This result is achieved by combining physical insights into the $i\varepsilon$ prescription in string theory with a new…

High Energy Physics - Theory · Physics 2026-02-25 Marco Maria Baccianti , Lorenz Eberhardt , Sebastian Mizera

We present new improved parton distributions for the photon. We fit {\bf all} available data on the photon structure function, $F^{\gamma}_{2}(x,Q^2)$, with $Q^2\ge 3$ GeV$^2$, in order to determine the quark distributions. We also pay…

High Energy Physics - Phenomenology · Physics 2011-07-19 L. E. Gordon , J. K. Storrow

We introduce the Dirac eigenmode filtering of topological charge density associated with Ginsparg-Wilson fermions as a tool to investigate the local structure of topological charge fluctuations in QCD. The resulting framework is used to…

High Energy Physics - Lattice · Physics 2008-11-26 I. Horvath , S. J. Dong , T. Draper , F. X. Lee , K. F. Liu , J. B. Zhang , H. B. Thacker

We consider the lattice topological charge density introduced by Hasenfratz, Laliena and Niedermayer and propose its eigenmode expansion as a tool to investigate the structure of topological charge fluctuations in QCD. The resulting…

High Energy Physics - Lattice · Physics 2008-11-26 I. Horvath , S. J. Dong , T. Draper , F. X. Lee , K. F. Liu , H. B. Thacker , J. B. Zhang

We investigate quantum chromodynamics (QCD) in this study by computing chiral-even generalized parton distributions (GPDs) at twist-$3$ using the light-front quark-diquark model (LFQDM), particularly when the longitudinal momentum transfer…

High Energy Physics - Phenomenology · Physics 2024-11-21 Sameer Jain , Shubham Sharma , Harleen Dahiya

Two-dimensional higher-order topological insulators can display a number of exotic phenomena such as half-integer charges localized at corners or disclination defects. In this paper, we analyze these phenomena, focusing on the paradigmatic…

Strongly Correlated Electrons · Physics 2023-01-11 Julian May-Mann , Taylor L. Hughes

We investigate the chiral-even twist-3 generalized parton distributions (GPDs) of valence quarks in the proton at nonzero skewness $\xi$, using a spectator model with scalar and axial-vector diquarks. We consider the exponential form factor…

High Energy Physics - Phenomenology · Physics 2024-07-25 Chentao Tan , Zhun Lu

A recent proposal for gauge-invariant observables in inflation [R. Brunetti et al., JHEP 1608 (2016) 032] is examined. We give a generalisation of their construction to general background spacetimes. In flat space, we calculate one-loop…

General Relativity and Quantum Cosmology · Physics 2018-02-02 Markus B. Fröb

We solve for the gluon generalized parton distributions (GPDs) inside the proton, focusing specifically on leading twist chiral-even GPDs. We obtain and employ the light-front wavefunctions (LFWFs) of the proton from a light-front quantized…

High Energy Physics - Phenomenology · Physics 2023-08-17 Bolang Lin , Sreeraj Nair , Siqi Xu , Zhi Hu , Chandan Mondal , Xingbo Zhao , James P. Vary