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Related papers: Valence Quark Transversity at Small $x$

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The QCD evolution of the unpolarized Transverse Momentum Dependent (TMD) distribution functions and of the Sivers functions have been discussed in recent papers. Following such results we reconsider previous extractions of the Sivers…

High Energy Physics - Phenomenology · Physics 2013-05-30 M. Anselmino , M. Boglione , S. Melis

We show possible transverse-momentum-dependent parton distribution functions (TMDs) for spin-1 hadrons including twist-3 and 4 functions in addition to the leading twist-2 ones by investigating all the possible decomposition of a quark…

High Energy Physics - Phenomenology · Physics 2021-05-12 S. Kumano , Qin-Tao Song

In this work, we have established the relations between the T-even proton transverse momentum-dependent parton distributions (TMDs) at all twist levels up to twist-4 using the light-front quark diquark model (LFQDM). From the…

High Energy Physics - Phenomenology · Physics 2024-11-21 Shubham Sharma , Satyajit Puhan , Narinder Kumar , Harleen Dahiya

Transverse parton momentum dependent distribution functions (TMDs) of the nucleon are studied in a covariant model, which describes the intrinsic motion of partons in terms of a covariant momentum distribution. The consistency of the…

High Energy Physics - Phenomenology · Physics 2009-09-02 A. V. Efremov , P. Schweitzer , O. V. Teryaev , P. Zavada

We present a review of current Transverse Momentum Dependent (TMD) phenomenology focusing our attention on the unpolarized TMD parton distribution function and the Sivers function. The paper introduces and comments about the new…

High Energy Physics - Phenomenology · Physics 2015-06-23 Stefano Melis

We set up a formalism for calculating transverse-momentum-dependent parton distribution functions (TMDs) using the tools of saturation physics. By generalizing the quasi-classical Glauber-Gribov-Mueller/McLerran-Venugopalan approximation to…

High Energy Physics - Phenomenology · Physics 2015-12-31 Yuri V. Kovchegov , Matthew D. Sievert

We study the small-$x$ asymptotics of unpolarized generalized parton distributions (GPDs) and generalized transverse momentum distributions (GTMDs). Unlike the previous works in the literature, we consider the case of non-zero (but small)…

High Energy Physics - Phenomenology · Physics 2026-05-07 Yuri V. Kovchegov , M. Gabriel Santiago , Huachen Sun

We calculate the leading twist valence quark transverse momentum parton distribution functions (TMDs) and generalized parton distributions (GPDs) of the charged kaons in an isospin symmetric nuclear matter at zero temperature by employing…

High Energy Physics - Phenomenology · Physics 2025-05-05 Reetanshu Pandey , Satyajit Puhan , Navpreet Kaur , Arvind Kumar , Suneel Dutt , Harleen Dahiya

We determine the small-$x$ asymptotics of the gluon helicity distribution in a proton at leading order in perturbative QCD at large $N_c$. To achieve this, we begin by evaluating the dipole gluon helicity TMD at small $x$. In the process we…

Nuclear Theory · Physics 2018-08-31 Yuri V. Kovchegov , Daniel Pitonyak , Matthew D. Sievert

In high-energy scattering processes involving two or more hadrons one can measure observables that are sensitive to partonic transverse momentum, which is encoded in so-called transverse momentum dependent (TMD) parton distribution…

High Energy Physics - Phenomenology · Physics 2016-10-27 Tom van Daal

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 present a covariant formulation and model calculations of transverse momentum-dependent quark distribution functions (TMDs) for spin-one hadrons. Emphasis is placed on a description of these 3-dimensional distribution functions which is…

Nuclear Theory · Physics 2017-11-01 Yu Ninomiya , Wolfgang Bentz , Ian C. Cloët

We point out that the analysis in arXiv:1003.0482 actually verifies the universality of transverse momentum dependent quark distributions at small $x$, which supports the observation in our earlier work arXiv:0904.4150. Once the gluon…

High Energy Physics - Phenomenology · Physics 2010-09-21 Hsiang-nan Li

We present an in-depth analysis of transverse momentum dependent (TMD) distributions of twist-three. In particular, we focus on evolution equations, symmetry relations, parameterization, interpretation, small-b asymptotic behaviour and the…

High Energy Physics - Phenomenology · Physics 2025-01-15 Simone Rodini , Alexey Vladimirov

A new type of parametrization for parton distribution functions in a proton, based on their $Q^2$-evolution at large and small $x$ values, is constructed. In our analysis, the valence and nonsinglet parts obey the Gross-Llewellyn-Smith and…

High Energy Physics - Phenomenology · Physics 2022-11-01 N. A. Abdulov , A. V. Kotikov , A. V. Lipatov

We show that the gauge-invariant transverse-momentum-dependent (TMD) quark distribution function can be expressed as a sum of all higher-twist collinear parton matrix elements in terms of a transport operator. From such a general…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zuo-tang Liang , Xin-Nian Wang , Jian Zhou

We review the present state of knowledge regarding the transverse polarisation (or transversity) distributions of quarks. After some generalities on transverse polarisation, we formally define the transversity distributions within the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Vincenzo Barone , Alessandro Drago , Philip G. Ratcliffe

In this paper we make re-analysis of a self-similarity based model of the proton structure function at small $x$ pursued in recent years. The additional assumption is that it should be singularity free in the entire kinematic range $0\leq…

High Energy Physics - Phenomenology · Physics 2016-05-05 D. K. Choudhury , Baishali Saikia

We compute the contribution of twist-2 and twist-3 parton distribution functions to the small-$b$ expansion for transverse momentum dependent (TMD) distributions at all powers of $b$. The computation is done by the twist-decomposition…

High Energy Physics - Phenomenology · Physics 2020-08-06 Valentin Moos , Alexey Vladimirov

The study of $\Lambda$ polarization in Semi-Inclusive Deep Inelastic Scattering (SIDIS) with a transversely polarized target has often been suggested as a privileged way to access transversity, as the initial quark polarization can be…

High Energy Physics - Experiment · Physics 2019-01-08 Andrea Moretti