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Related papers: Unintegrated parton densities at small x

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We update the phenomenological parameters of the Transverse Momentum Dependent (TMD, or unintegrated) gluon density in a proton proposed in our previous studies. This analysis is based on the analytical expression for starting gluon…

High Energy Physics - Phenomenology · Physics 2024-04-16 A. V. Lipatov , G. I. Lykasov , M. A. Malyshev

We review the information on the spin and orbital angular momentum structure of the nucleon encoded in the T-even transverse momentum dependent parton distributions within light-cone quark models. Model results for azimuthal spin…

High Energy Physics - Phenomenology · Physics 2009-12-10 B. Pasquini , S. Boffi , A. V. Efremov , P. Schweitzer

We solve a unified integral equation to obtain the $x, Q_T$ and $Q$ dependence of the gluon distribution of a proton in the small $x$ regime; where $x$ and $Q_T$ are the longitudinal momentum fraction and the transverse momentum of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Kwiecinski , A. D. Martin , P. J. Sutton

The quark spin densities related to generalized parton distributions in impact-parameter space and to transverse-momentum dependent parton distributions are reviewed within a light-cone quark model, with focus on the role of the different…

High Energy Physics - Phenomenology · Physics 2015-05-14 B. Pasquini , S. Boffi , P. Schweitzer

We fit the reduced cross section for deep-inelastic electron scattering data to a three parameter ln^2 s fit, A + beta ln^2 (s/s_0), where s= [Q^2/x] (1-x) + m^2, and Q^2 is the virtuality of the exchanged photon. Over a wide range in Q^2…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. M. Block , E. L. Berger , C. -I. Tan

We summarize recent progress in understanding the effects of nonperturbative short-range interactions in QCD on the nucleon's partonic structure at a low scale: (a) Sea quarks have intrinsic transverse momenta up to the chiral…

High Energy Physics - Phenomenology · Physics 2012-12-18 P. Schweitzer , M. Strikman , C. Weiss

We present for first time the computation at large $q_T$ (or small $b_T$) matching coefficients of Transverse Momentum Dependent Parton Distribution Function (TMDPDF) for linearly polarised to the integrated gluon distribution at…

High Energy Physics - Phenomenology · Physics 2019-08-19 Daniel Gutierrez-Reyes , Sergio Leal Gómez , Ignazio Scimemi , Alexey Vladimirov

We study the associated production of real (isolated) or virtual photons (with their subsequent leptonic decay) and hadronic jets in proton-proton collisions at the LHC using the $k_T$-factorization approach of QCD. The consideration is…

High Energy Physics - Phenomenology · Physics 2014-11-12 A. V. Lipatov , N. P. Zotov

We present the construction of unintegrated double parton distribution functions which include dependence on transverse momenta of partons. We extend the formulation which was used to obtain the single unintegrated parton distributions from…

High Energy Physics - Phenomenology · Physics 2017-03-08 K. Golec-Biernat , A. M. Stasto

Quarks and gluon, as quantum particles, are subjects to various effects that go beyond the naive parton picture and are not captured by ordinary parton densities. In this work, we investigate the twist-three parton distribution functions,…

High Energy Physics - Phenomenology · Physics 2025-11-07 Alexey Vladimirov , Guillermo Portela , Simone Rodini

Unraveling the inner dynamics of gluons and quarks inside nucleons is a primary target of studies at new-generation colliding machines. Finding an answer to fundamental problems of Quantum ChromoDynamics, such as the origin of nucleon mass…

High Energy Physics - Phenomenology · Physics 2022-12-27 Francesco Giovanni Celiberto

Recently, the definitions of the Kimber-Martin-Ryskin-Watt (KMRW) unintegrated parton densities (UPDFs) have been discussed by several groups. In the first part of this manuscript, we remind the issues encountered with these definitions and…

High Energy Physics - Phenomenology · Physics 2024-07-30 Benjamin Guiot

We obtain the leading-twist valence quark transverse-momentum-dependent parton distribution functions (TMD PDFs) for the proton within the basis light-front quantization (BLFQ) framework. Our results are consistent with lattice QCD…

High Energy Physics - Phenomenology · Physics 2022-08-22 Zhi Hu , Siqi Xu , Chandan Mondal , Xingbo Zhao , James P. Vary

We study the transverse momentum dependent (TMD) parton distributions at small-x in a consistent framework that takes into account the TMD evolution and small-x evolution simultaneously. The small-x evolution effects are included by…

High Energy Physics - Phenomenology · Physics 2017-06-28 Bo-Wen Xiao , Feng Yuan , Jian Zhou

We study the rapidity evolution of gluon transverse momentum dependent distributions appearing in processes of particle production and show how this evolution changes from small to moderate Bjorken x.

High Energy Physics - Phenomenology · Physics 2016-07-20 I. Balitsky , A. Tarasov

One of the most interesting consequence of non-zero intrinsic transverse momentum of partons in the nucleon is the nontrivial azimuthal dependence of the cross section of hard scattering processes. Many of the observable asymmetries contain…

High Energy Physics - Phenomenology · Physics 2009-11-07 K. A. Oganessyan , L. S. Asilyan , E. De Sanctis , V. Muccifora

In order to obtain polarised parton densities we have made next to leading order QCD fit using experimental data on deep inelastic structure functions on nucleons. This fit is compared with the updated fit to coresponding spin asymmetries.…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jan Bartelski , Stanislaw Tatur

We calculate the unintegrated gluon distribution at low intrinsic transverse momenta and its parameters are found from the best description of the SPS and LHC data on the $pp$ collision in the soft kinematical region. It allows us to study…

High Energy Physics - Phenomenology · Physics 2015-06-12 G. I. Lykasov , A. A. Grinyuk , V. A. Bednyakov

Highly energetic particles in the medium of a quark gluon plasma undergo processes of coherent medium induced radiation and scatterings off medium particles. We solved the evolution equations for particle fragmentation functions that…

High Energy Physics - Phenomenology · Physics 2021-11-17 E. Blanco , K. Kutak , M. Rohrmoser , W. Płaczek , R. Straka

We present approximations of varying degree of sophistication to the integral equations for the (gluon) structure functions of a hadron (``the partonic flux factor'') in a model valid in the Leading Log Approximation with a running coupling…

High Energy Physics - Phenomenology · Physics 2009-10-30 B. Andersson , G. Gustafson , H. Kharraziha