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Related papers: Small-$x$ Asymptotics of the Gluon Helicity Distri…

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We propose new Transverse Momentum Dependent (TMD) gluon densities in nuclei. Our method is based on a combination of the color dipole scattering formalism, within which we interpret the nuclear deep inelastic structure functions…

High Energy Physics - Phenomenology · Physics 2025-05-06 A. V. Lipatov , G. I. Lykasov , M. A. Malyshev

We consider the azimuthal $\cos \varphi$ and $\cos 2\varphi$ distributions and the Callan-Gross ratio $R={\rm d}\sigma_L/{\rm d}\sigma_T$ in heavy-quark pair electroproduction, $lN\rightarrow l^{\prime}Q\bar{Q}X$, as probes of linearly…

High Energy Physics - Phenomenology · Physics 2020-01-24 N. Ya. Ivanov , A. V. Efremov , O. V. Teryaev

How quarks and gluons conspire to provide the total spin of proton is a long-standing puzzle in quantum chromodynamics (QCD). The unique capability of RHIC, that can provide longitudinally polarized $p+p$ collisions at both $\sqrt{s} = 200$…

High Energy Physics - Experiment · Physics 2024-02-26 Ting Lin

We study open b\bar{b} production at large rapidity at the LHC in an attempt to pin down the gluon distribution at very low x. For the LHC energy of 7 TeV, at next-to-leading order (NLO), there is a large factorization scale uncertainty. We…

High Energy Physics - Phenomenology · Physics 2015-05-28 E. G. de Oliveira , A. D. Martin , M. G. Ryskin

$J/\psi$- or $\Upsilon$-pair production at the LHC are promising processes to study the gluon transverse momentum distributions (TMDs) which remain very poorly known. In this article, we improve on previous results by including the TMD…

High Energy Physics - Phenomenology · Physics 2020-02-26 Florent Scarpa , Daniël Boer , Miguel G. Echevarria , Jean-Philippe Lansberg , Cristian Pisano , Marc Schlegel

Two widely proposed kt-dependent gluon distributions in the small-x saturation regime are investigated using two particle back-to-back correlations in high energy scattering processes. The Weizsacker-Williams gluon distribution, interpreted…

High Energy Physics - Phenomenology · Physics 2011-02-01 Fabio Dominguez , Bo-Wen Xiao , Feng Yuan

I discuss the p_t distributions for high-multiplicity events originating from semi-classical variation of the gluon density of the proton.The multiplicity distribution measures the curvature of the effective action for the small-x gluon…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Dumitru

We study the helicity distributions of light flavor quark-antiquark ($q \bar{q}$) pairs in the nucleon sea. The valence quarks are handled by adopting the light-cone SU(6) quark-spectator-diquark model and the sea $q \bar{q}$ pairs are…

High Energy Physics - Phenomenology · Physics 2018-09-12 Mengyun Liu , Bo-Qiang Ma

We apply the formalism developed earlier for studying transverse momentum dependent parton distribution functions (TMDs) at small Bjorken $x$ to construct the small-$x$ asymptotics of the quark Sivers function. First, we explicitly…

High Energy Physics - Phenomenology · Physics 2022-09-16 Yuri V. Kovchegov , M. Gabriel Santiago

We explore the evolution of the Deep Inelastic Scattering (DIS) entropy, defined as $ S(x,\mu^2) \simeq \ln[xg(x,\mu^2)]$ at small Bjorken variable $x$, where $\mu$ is the observable scale and the gluon distribution $xg(x,\mu^2)$ is derived…

High Energy Physics - Phenomenology · Physics 2026-01-09 G. R. Boroun , Phuoc Ha

The BFKL and the unified angular-ordered equations are solved to determine the gluon distribution at small $x$. The impact of kinematic constraints is investigated. Predictions are made for observables sensitive to the gluon at small $x$.…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Kwiecinski , A. D. Martin , P. J. Sutton

We present a study of the contribution of antishadowing effects on the gluon distribution functions $G(x,Q^2)$ in light of the Gribov-Levin-Ryskin-Mueller-Qiu, Zhu-Ruan-Shen (GLR-MQ-ZRS) nonlinear equation at small-$x$, where $x$ is the…

High Energy Physics - Phenomenology · Physics 2019-09-25 M. Lalung , P. Phukan , J. K. Sarma

We investigate the possibility to draw conclusions on the sign of the spin-dependent gluon distribution, $\Delta G(x, Q^2)$, from existing polarized DIS data. The spin-dependent parton distributions $\Delta u_v, \Delta d_v, \Delta {\bar u},…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. -D. Nowak , A. V. Sidorov , M. V. Tokarev

We explore the possibility whether the gluon helicity distribution $\Delta G(x)$ can be extracted from a comparison of experimental data on the longitudinal spin-spin asymmetry $A_{LL}$ in $\gamma p$ diffractive deep inelastic scattering…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. I. Manayenkov

Using continuum Schwinger function methods, a coherent set of predictions for proton, $\Lambda$ and $\Sigma^0$ distribution functions (DFs) has been made available -- both helicity dependent and unpolarised. The results and comparisons…

High Energy Physics - Phenomenology · Physics 2026-01-07 Yang Yu , Peng Cheng , Hui-Yu Xing , Daniele Binosi , Craig D. Roberts

We make a critical study of the relationship between the singlet structure function $F_{2}^{S}$ and the gluon distribution $G(x,Q^{2})$ proposed in the past two decades, which is frequently used to extract the gluon distribution from the…

High Energy Physics - Phenomenology · Physics 2014-04-22 G. R. Boroun

We compute the helicity-dependent strange quark distribution in the proton in the framework of chiral effective theory. Starting from the most general chiral SU(3) Lagrangian that respects Lorentz and gauge invariance, we derive the…

High Energy Physics - Phenomenology · Physics 2021-01-01 X. G. Wang , Chueng-Ryong Ji , W. Melnitchouk , Y. Salamu , A. W. Thomas , P. Wang

A QCD analysis of the world data on polarized deep inelastic scattering is presented in leading and next-to-leading order. New parameterizations are derived for the quark and gluon distributions for the kinematic range $x \epsilon…

High Energy Physics - Phenomenology · Physics 2016-09-06 J. Blümlein , H. Böttcher

Measurements involving the gluon spin density, Delta G=G++ - G+-, can play an important role in the quantitative understanding of proton structure. To demonstrate this, we show that the shape of the gluon asymmetry, A(x,t)=Delta…

High Energy Physics - Phenomenology · Physics 2011-07-27 Yevgeny Binder , Gordon P. Ramsey , Dennis Sivers

Deviation of the multiplicity distribution $P_q$ in small bin from its Poisson counterpart $p_q$ is studied within the Ginzburg-Landau description for second-order quark-hadron phase transition. Dynamical factor $d_q\equiv P_q/p_q$ for the…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. B. Yang , X. Cai