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Related papers: Orbital Angular Momentum at Small $x$ Revisited

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We derive the consequences of the Myhrer-Thomas explanation of the proton spin problem for the distribution of orbital angular momentum on the valence and sea quarks. After QCD evolution these results are found to be in very good agreement…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. W. Thomas

Plasmons of quark-gluon plasma - gluon collective modes - are systematically studied. The plasma is, in general, non-equilibrium but homogeneous. We consider anisotropic momentum distributions of plasma constituents which are obtained from…

High Energy Physics - Phenomenology · Physics 2014-10-16 Margaret E. Carrington , Katarzyna Deja , Stanislaw Mrowczynski

It is well-known that the back-to-back (correlation) limit of inclusive quark-antiquark dijet production in unpolarized high energy electron-proton collisions can probe the Weizs\"{a}cker-Williams (WW) gluon transverse momentum-dependent…

High Energy Physics - Phenomenology · Physics 2025-04-18 Yuri V. Kovchegov , Ming Li

Orbital angular momentum (OAM) light possesses in addition to its usual helicity ($s=\pm \hbar$, depending on its circular polarization) an orbital angular momentum $l$. This means that in principle one can transfer more than a single…

We compute the complete set of the leading-twist gluon and sea-quark generalized transverse momentum distributions (GTMDs) in the small-$x$, or eikonal, approximation at vanishing skewness $\xi = 0$. All the gluon GTMDs become expressed in…

High Energy Physics - Phenomenology · Physics 2026-03-09 Sanjin Benić , Yoshikazu Hagiwara , Boris Šarić , Eric Andreas Vivoda

Motivated by recent progress in the generation of optical spatiotemporal vortex pulses (STVPs), there is a theoretical discussion about the transverse orbital angular momentum (OAM) carried by such pulses. Two recent works [K. Y. Bliokh,…

Optics · Physics 2023-03-20 Konstantin Y. Bliokh

The flavor-dependent valence, sea quark and antiquark spin distributions can be determined separately from theoretical assumptions and experimental data. We have determined the valence distributions using the Bjorken sum rule and have…

High Energy Physics - Phenomenology · Physics 2014-11-17 Gordon P. Ramsey

In this work we aim to gain qualitative insight on the far-from-equilibrium behavior of the gluon plasma produced in the early stages of a heavy-ion collision. It was recently discovered arXiv:1810.10554 that the distribution functions of…

High Energy Physics - Phenomenology · Physics 2022-06-08 Jasmine Brewer , Bruno Scheihing-Hitschfeld , Yi Yin

We present first calculations of the fluctuating gluon distribution in a proton as a function of impact parameter and rapidity employing the functional Langevin form of the JIMWLK renormalization group equation. We demonstrate that when…

High Energy Physics - Phenomenology · Physics 2015-06-22 Soeren Schlichting , Bjoern Schenke

We investigate the close connection between the quantum phase space Wigner distribution of small-$x$ gluons and the color dipole scattering amplitude, and propose to study it experimentally in the hard diffractive dijet production at the…

High Energy Physics - Phenomenology · Physics 2016-05-25 Yoshitaka Hatta , Bo-Wen Xiao , Feng Yuan

We developed a new and unified scheme for describing both quark spin and orbital angular momenta in symmetry-breaking chiral quark model. The loss of quark spin in the chiral splitting processes is compensated by the gain of the orbital…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xiaotong Song

The leading order evolution of parton orbital angular momenta is treated in the probabilistic manner. As a result, the splitting probability matrix, while coinciding with the recent explicit calculations, is expressed in the terms of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 O. V. Teryaev

We calculate the quark orbital angular momentum of the nucleon from the quark energy-momentum tensor form factors on the lattice. The disconnected insertion is estimated stochastically which employs the $Z_2$ noise with an unbiased…

High Energy Physics - Phenomenology · Physics 2016-09-06 N. Mathur , S. J. Dong , K. F. Liu , L. Mankiewicz , N. C. Mukhopadhyay

We investigate the quark orbital angular momentum of the nucleon in the absence of gauge-field degrees of freedom, by using the concept of the Wigner distribution and the light-cone wave functions of the Fock state expansion of the nucleon.…

High Energy Physics - Phenomenology · Physics 2015-06-03 C. Lorce' , B. Pasquini , X. Xiong , F. Yuan

The paper reports analysis of momentum fractions carried by quarks and gluons in models of Proton structure functions at small $x$. First, we analyze the model proposed by Lastovicka based on self-similarity sometime back. We then make a…

High Energy Physics - Phenomenology · Physics 2017-08-02 D K Choudhury , Baishali Saikia , K Kalita

We study the evolution behavior of generalized parton distributions at small longitudinal momentum fraction. Particular attention is paid to the ratio of a generalized parton distribution and its forward limit, to the mixing between quarks…

High Energy Physics - Phenomenology · Physics 2008-11-26 Markus Diehl , Wolfgang Kugler

We consider the interaction of the partonic fluctuation of a scalar ``photon'' with an external color field to calculate the leading and next-to-leading order gluon distribution of the proton following the work done by…

High Energy Physics - Phenomenology · Physics 2009-11-10 H. -J. Pirner , A. I. Shoshi , G. Soyez

We study the orbital angular momentum contribution to the spin structure of the proton. It is well known that the quark and gluon spin contributions do not add up to the proton spin. We motivate the connection between the Generalized…

High Energy Physics - Phenomenology · Physics 2016-02-02 Abha Rajan , Simonetta Liuti

We report on the first global analysis of transverse momentum dependent helicity distributions of the proton. The analysis is performed at next-to-leading order with the evolution factor at next-to-next-to-leading-logarithmic accuracy.…

High Energy Physics - Phenomenology · Physics 2025-04-01 Ke Yang , Tianbo Liu , Peng Sun , Yuxiang Zhao , Bo-Qiang Ma

We argue that due to Parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions -- the generalized transverse momentum distributions -- that describes the configuration of an…

High Energy Physics - Phenomenology · Physics 2015-06-17 Aurore Courtoy , Gary R. Goldstein , J. Osvaldo Gonzalez Hernandez , Simonetta Liuti , Abha Rajan